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Lee FK, Greene C, Mercer K, Taylor J, Yazdanpanah G, Vogt R, Lee R, Cuthbert C, Cordovado S. CDC's Laboratory Activities to Support Newborn Screening for Spinal Muscular Atrophy. Int J Neonatal Screen 2024; 10:51. [PMID: 39051407 PMCID: PMC11270301 DOI: 10.3390/ijns10030051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/23/2024] [Revised: 06/23/2024] [Accepted: 07/10/2024] [Indexed: 07/27/2024] Open
Abstract
Spinal muscular atrophy (SMA) was added to the HHS Secretary's Recommended Uniform Screening Panel for newborn screening (NBS) in 2018, enabling early diagnosis and treatment of impacted infants to prevent irreversible motor neuron damage. In anticipation of supporting SMA newborn screening, scientists at the U.S. Centers for Disease Control and Prevention (CDC) have worked towards building resources for public health laboratories in four phases since 2013. In Phase 1, CDC established a real-time PCR assay, which uses a locked nucleic acid probe to attain the needed specificity, to detect SMN1 exon 7. In Phase 2, we developed quality assurance dried blood spot materials made with transduced lymphoblast cell lines established from de-identified SMA patients, carriers, and unaffected donors. In 2021, CDC implemented Phase 3, a proficiency testing program, that now supports 115 NBS labs around the world. We are currently completing Phase 4, which includes the implementation of an external SMA quality control material program. Also, during this time, CDC has provided individual technical assistance to NBS programs and bench training to NBS scientists during our annual molecular workshop. These CDC-led activities have contributed to the rapid and full implementation of SMA screening in all 50 U.S. states as of February 2024.
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Affiliation(s)
- Francis K. Lee
- Newborn Screening and Molecular Biology Branch, U.S. Centers for Disease Control and Prevention, Atlanta, GA 30341, USA; (C.G.); (K.M.); (J.T.); (G.Y.); (R.V.); (R.L.); (C.C.); (S.C.)
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Opmeer L, Gazzoli I, Ballmann M, Willemsen M, Voshol GP, Grudniewska-Lawton M, Havenga M, Yallop C, Hamidi A, Gillissen G, Bakker WAM. High throughput AS LNA qPCR method for the detection of a specific mutation in poliovirus vaccine strains. Vaccine 2024; 42:2475-2484. [PMID: 38503660 PMCID: PMC11007389 DOI: 10.1016/j.vaccine.2024.01.103] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2023] [Revised: 11/21/2023] [Accepted: 01/30/2024] [Indexed: 03/21/2024]
Abstract
Sabin Inactivated Poliovirus Vaccine (sIPV) has become one of the preferred vaccination options for the last step in the Poliovirus eradication program. Sequencing of poliovirus samples is needed during the manufacturing of poliovirus vaccines to assure the safety and immunogenicity of these vaccines. Next-generation sequencing analysis is the current costly and time-consuming gold standard for monitoring the manufacturing processes. We developed a low-cost and quick, highly sensitive, and allele-specific locked nucleic acid-probe-based reverse transcription quantitative PCR alternative that can accurately detect mutations in poliovirus vaccine samples during process development, scaling up, and release. Using the frequently in vitro occurring and viral replication-impacting VP1-E295K mutation as a showcase, we show that this technology can accurately detect E295K mutations in poliovirus 2 samples to similar levels as NGS. The qPCR technology was developed employing a synthetic dsDNA fragment-based standard curve containing mixes of E295K-WT (wildtype) and Mut (mutant) synthetic dsDNA fragments ranging from 1 × 107 copies/µL to 1 × 102 copies/µL to achieve a linear correlation with R2 > 0.999, and PCR efficiencies of 95-105 %. Individual standard concentration levels achieved accuracies of ≥92 % (average 96 %) and precisions of ≤17 % (average 3.3 %) RSD. Specificity of locked nucleic acid (LNA)-probes was confirmed in the presence and absence of co-mutations in the probe-binding region. Application of the developed assay to Sabin Poliovirus type 2 production run samples, illustrated a linear relationship with an R2 of 0.994, and an average accuracy of 97.2 % of the variant (allele)-specific AS LNA qPCR result, compared to NGS. The assay showed good sensitivity for poliovirus samples, containing E295K mutation levels between 0 % and 95 % (quantification range). In conclusion, the developed AS LNA qPCR presents a valuable low-cost, and fast tool, suitable for the process development and quality control of polio vaccines.
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Affiliation(s)
- Lizet Opmeer
- Batavia Biosciences B.V., Bioscience Park Leiden, Zernikedreef 16, 2333CL Leiden, The Netherlands
| | - Isabella Gazzoli
- Batavia Biosciences B.V., Bioscience Park Leiden, Zernikedreef 16, 2333CL Leiden, The Netherlands
| | - Mónika Ballmann
- Batavia Biosciences B.V., Bioscience Park Leiden, Zernikedreef 16, 2333CL Leiden, The Netherlands
| | - Marieke Willemsen
- Batavia Biosciences B.V., Bioscience Park Leiden, Zernikedreef 16, 2333CL Leiden, The Netherlands
| | - Gerben P Voshol
- GenomeScan B.V., Plesmanlaan 1d, 2333 BZ Leiden, The Netherlands
| | | | - Menzo Havenga
- Batavia Biosciences B.V., Bioscience Park Leiden, Zernikedreef 16, 2333CL Leiden, The Netherlands
| | - Christopher Yallop
- Batavia Biosciences B.V., Bioscience Park Leiden, Zernikedreef 16, 2333CL Leiden, The Netherlands
| | - Ahd Hamidi
- Batavia Biosciences B.V., Bioscience Park Leiden, Zernikedreef 16, 2333CL Leiden, The Netherlands
| | - Gert Gillissen
- Batavia Biosciences B.V., Bioscience Park Leiden, Zernikedreef 16, 2333CL Leiden, The Netherlands
| | - Wilfried A M Bakker
- Batavia Biosciences B.V., Bioscience Park Leiden, Zernikedreef 16, 2333CL Leiden, The Netherlands.
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Liu Z, Li X, Zhang R, Ji L, Gong L, Ji Y, Zhou F, Yin Y, Li K, Sun P, Pu Z, Wang Q, Zou J. Identification of DNA variants at ultra-low variant allele frequencies via Taq polymerase cleavage of wild-specific blockers. Anal Bioanal Chem 2023; 415:6537-6549. [PMID: 37702773 DOI: 10.1007/s00216-023-04931-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Revised: 08/27/2023] [Accepted: 08/29/2023] [Indexed: 09/14/2023]
Abstract
Detecting mutations related to tumors holds immense clinical significance for cancer diagnosis and treatment. However, the presence of highly redundant wild DNA poses a challenge for the advancement of low-copy mutant ctDNA genotyping in cancer cases. To address this, a Taqman qPCR strategy to identify rare mutations at low variant allele fractions (VAFs) has been developed. This strategy combines mutant-specific primers with wild-specific blockers. Diverging from other blocker-mediated PCRs, which rely on primer-induced strand displacement or the use of modified oligos resistant to Taq polymerase, our innovation is built upon the cleavage of specific blockers by Taq polymerase. Given its unique design, which does not hinge on strand displacement or base modification, we refer to this novel method as unmodified-blocker cleavage PCR (UBC-PCR). Multiple experiments consistently confirmed that variant distinction was improved significantly by introduction of 5' unmatched blockers into the reaction. Moreover, UBC-PCR successfully detected mutant DNA at VAFs as low as 0.01% across six different variant contexts. Multiplex UBC-PCR was also performed to identify a reference target and three mutations with a sensitivity of 0.01% VAFs in one single tube. In profiling the gene status from 12 lung cancer ctDNA samples and 22 thyroid cancer FNA DNA samples, UBC-PCR exhibited a 100% concordance rate with ddPCR and a commercial ARMS kit, respectively. Our work demonstrates that UBC-PCR can identify low-abundance variants with high sensitivity in multiplex reactions, independent of strand displacement and base modification. This strategy holds the potential to significantly impact clinical practice and precision medicine.
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Affiliation(s)
- Zhaocheng Liu
- Department of Laboratory Medicine, The Affiliated Wuxi People's Hospital of Nanjing Medical University, Wuxi People's Hospital, Wuxi Medical Center, Nanjing Medical University, 299 Qingyang Road, Wuxi, 214023, Jiangsu, China
- Center of Clinical Research, The Affiliated Wuxi People's Hospital of Nanjing Medical University, Wuxi People's Hospital, Wuxi Medical Center, Nanjing Medical University, Wuxi, 214023, Jiangsu, China
| | - Xiushuai Li
- Department of Neurosurgery, The Affiliated Wuxi Second Hospital of Nanjing Medical University, 68 Zhongshan Road, Wuxi, 214122, Jiangsu Province, China
| | - Rui Zhang
- Department of Laboratory Medicine, The Affiliated Wuxi People's Hospital of Nanjing Medical University, Wuxi People's Hospital, Wuxi Medical Center, Nanjing Medical University, 299 Qingyang Road, Wuxi, 214023, Jiangsu, China
- Center of Clinical Research, The Affiliated Wuxi People's Hospital of Nanjing Medical University, Wuxi People's Hospital, Wuxi Medical Center, Nanjing Medical University, Wuxi, 214023, Jiangsu, China
| | - Li Ji
- Department of Laboratory Medicine, The Affiliated Wuxi People's Hospital of Nanjing Medical University, Wuxi People's Hospital, Wuxi Medical Center, Nanjing Medical University, 299 Qingyang Road, Wuxi, 214023, Jiangsu, China
- Center of Clinical Research, The Affiliated Wuxi People's Hospital of Nanjing Medical University, Wuxi People's Hospital, Wuxi Medical Center, Nanjing Medical University, Wuxi, 214023, Jiangsu, China
| | - Lingli Gong
- Department of Laboratory Medicine, The Affiliated Wuxi People's Hospital of Nanjing Medical University, Wuxi People's Hospital, Wuxi Medical Center, Nanjing Medical University, 299 Qingyang Road, Wuxi, 214023, Jiangsu, China
- Center of Clinical Research, The Affiliated Wuxi People's Hospital of Nanjing Medical University, Wuxi People's Hospital, Wuxi Medical Center, Nanjing Medical University, Wuxi, 214023, Jiangsu, China
| | - Yong Ji
- Department of Thoracic Surgery, The Affiliated Wuxi People's Hospital of Nanjing Medical University, Wuxi People's Hospital, Wuxi Medical Center, Nanjing Medical University, Wuxi, 214023, Jiangsu, China
| | - Fengsheng Zhou
- Department of Ultrasound, The Affiliated Wuxi People's Hospital of Nanjing Medical University, Wuxi People's Hospital, Wuxi Medical Center, Nanjing Medical University, Wuxi, 214023, Jiangsu, China
| | - Ying Yin
- Department of Laboratory Medicine, The Affiliated Wuxi People's Hospital of Nanjing Medical University, Wuxi People's Hospital, Wuxi Medical Center, Nanjing Medical University, 299 Qingyang Road, Wuxi, 214023, Jiangsu, China
- Center of Clinical Research, The Affiliated Wuxi People's Hospital of Nanjing Medical University, Wuxi People's Hospital, Wuxi Medical Center, Nanjing Medical University, Wuxi, 214023, Jiangsu, China
| | - Koukou Li
- Department of Laboratory Medicine, The Affiliated Wuxi People's Hospital of Nanjing Medical University, Wuxi People's Hospital, Wuxi Medical Center, Nanjing Medical University, 299 Qingyang Road, Wuxi, 214023, Jiangsu, China
- Center of Clinical Research, The Affiliated Wuxi People's Hospital of Nanjing Medical University, Wuxi People's Hospital, Wuxi Medical Center, Nanjing Medical University, Wuxi, 214023, Jiangsu, China
| | - Ping Sun
- Department of Pathology, Jiangnan University Medical Center, Wuxi, 214023, Jiangsu, China
| | - Zhening Pu
- Department of Laboratory Medicine, The Affiliated Wuxi People's Hospital of Nanjing Medical University, Wuxi People's Hospital, Wuxi Medical Center, Nanjing Medical University, 299 Qingyang Road, Wuxi, 214023, Jiangsu, China
- Center of Clinical Research, The Affiliated Wuxi People's Hospital of Nanjing Medical University, Wuxi People's Hospital, Wuxi Medical Center, Nanjing Medical University, Wuxi, 214023, Jiangsu, China
| | - Qing Wang
- Department of Neurosurgery, The Affiliated Wuxi Second Hospital of Nanjing Medical University, 68 Zhongshan Road, Wuxi, 214122, Jiangsu Province, China.
| | - Jian Zou
- Department of Laboratory Medicine, The Affiliated Wuxi People's Hospital of Nanjing Medical University, Wuxi People's Hospital, Wuxi Medical Center, Nanjing Medical University, 299 Qingyang Road, Wuxi, 214023, Jiangsu, China.
- Center of Clinical Research, The Affiliated Wuxi People's Hospital of Nanjing Medical University, Wuxi People's Hospital, Wuxi Medical Center, Nanjing Medical University, Wuxi, 214023, Jiangsu, China.
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Liu Z, Zhang R, Jiang X, Ji L, Sun P, Ji Y, Zhang Y, Ding Y, Li K, Pu Z, Zhou F, Zou J. Highly Sensitive Enrichment of Low-Frequency Variants by Hairpin Competition Amplification. Anal Chem 2023; 95:12015-12023. [PMID: 37527514 DOI: 10.1021/acs.analchem.3c01803] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/03/2023]
Abstract
Gene mutations are inevitably accumulated in cells of the human body. It is of great significance to detect mutations at the earliest possible time in physiological and pathological processes. However, genotyping low-copy tumor DNA (ctDNA) in patients is challenging due to abundant wild DNA backgrounds. One novel strategy to enrich rare mutations at low variant allele fractions (VAFs) with quantitative polymerase chain reaction (qPCR) and Sanger sequencing was contrived by introducing artificial hairpins into amplicons to compete with primers, coined as the hairpin competition amplification (HCA) system. The influence imposed by artificial hairpins on primer-binding in a high-temperature PCR system was investigated for the first time in this work, paving the way for the optimization of HCA. HCA differs from the previously reported work in which hairpins are formed to inhibit extension of wild-type DNA using 5-exonuclease-negative polymerase, where the readout is dependent on melting curve analysis after asymmetric PCR. Targeted at six different variants, HCA qPCR and HCA Sanger-enriched mutant DNA at VAFs as low as 0.1 or 0.01% were performed. HCA demonstrated advantages in multiplex reaction and temperature robustness. In profiling gene status from 12 lung cancer ctDNA samples and 16 thyroid cancer FNA DNA samples, HCA demonstrated a 100% concordance rate compared to ddPCR and commercial ARMS kit. HCA qPCR and Sanger sequencing can enrich low-abundance variants with high sensitivity and temperature robustness, presenting a novel and effective tool for precision diagnosis and treatment of rare variant diseases.
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Affiliation(s)
- Zhaocheng Liu
- Department of Laboratory Medicine, The Affiliated Wuxi People's Hospital of Nanjing Medical University, Wuxi 214023, China
- Center of Clinical Research, The Affiliated Wuxi People's Hospital of Nanjing Medical University, Wuxi 214023, Jiangsu, China
| | - Rui Zhang
- Department of Laboratory Medicine, The Affiliated Wuxi People's Hospital of Nanjing Medical University, Wuxi 214023, China
- Center of Clinical Research, The Affiliated Wuxi People's Hospital of Nanjing Medical University, Wuxi 214023, Jiangsu, China
| | - Xixi Jiang
- Department of Laboratory Medicine, The Affiliated Wuxi People's Hospital of Nanjing Medical University, Wuxi 214023, China
| | - Li Ji
- Department of Laboratory Medicine, The Affiliated Wuxi People's Hospital of Nanjing Medical University, Wuxi 214023, China
- Center of Clinical Research, The Affiliated Wuxi People's Hospital of Nanjing Medical University, Wuxi 214023, Jiangsu, China
| | - Ping Sun
- Department of Pathology, Jiangnan University Medical Center, Wuxi 214023, Jiangsu, China
| | - Yong Ji
- Department of Thoracic Surgery, The Affiliated Wuxi People's Hospital of Nanjing Medical University, Wuxi 214023, Jiangsu, China
| | - Yu Zhang
- Department of Ultrasound, The Affiliated Wuxi People's Hospital of Nanjing Medical University, Wuxi 214023, Jiangsu, China
| | - Yan Ding
- Department of Ultrasound, The Affiliated Wuxi People's Hospital of Nanjing Medical University, Wuxi 214023, Jiangsu, China
| | - Koukou Li
- Department of Laboratory Medicine, The Affiliated Wuxi People's Hospital of Nanjing Medical University, Wuxi 214023, China
- Center of Clinical Research, The Affiliated Wuxi People's Hospital of Nanjing Medical University, Wuxi 214023, Jiangsu, China
| | - Zhening Pu
- Department of Laboratory Medicine, The Affiliated Wuxi People's Hospital of Nanjing Medical University, Wuxi 214023, China
- Center of Clinical Research, The Affiliated Wuxi People's Hospital of Nanjing Medical University, Wuxi 214023, Jiangsu, China
| | - Fengsheng Zhou
- Department of Ultrasound, The Affiliated Wuxi People's Hospital of Nanjing Medical University, Wuxi 214023, Jiangsu, China
| | - Jian Zou
- Department of Laboratory Medicine, The Affiliated Wuxi People's Hospital of Nanjing Medical University, Wuxi 214023, China
- Center of Clinical Research, The Affiliated Wuxi People's Hospital of Nanjing Medical University, Wuxi 214023, Jiangsu, China
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Chen FE, Wang J, Nambiar AH, Hardick J, Melendez J, Trick AY, Wang TH. Point-of-Care Amenable Detection of Mycoplasma genitalium and Its Antibiotic Resistance Mutations. ACS Sens 2023; 8:1550-1557. [PMID: 36961769 PMCID: PMC11257175 DOI: 10.1021/acssensors.2c02630] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/25/2023]
Abstract
Mycoplasma genitalium (MG) is an emerging sexually transmitted bacterium. Due to its fastidious and slow-growing nature, MG is difficult to detect through culture-based diagnostics. Like Neisseria gonorrheae, another bacterial pathogen linked to sexually transmitted infections (STIs), MG has developed resistance to macrolide and fluoroquinolone antibiotics used to treat STIs. The ability to detect MG and identify genomic mutations associated with antibiotic resistance simultaneously can enable antibiotic stewardship and mitigate the spread of antibiotic-resistant MG. Toward this end, we first developed a multiplexed probe-based PCR-melt assay that detects MG and the presence of macrolide resistance mutations in the 23S rRNA gene and fluoroquinolone resistance mutations in the parC gene. Each target was identified via its unique combination of fluorescence label and melting temperature. This approach allowed differentiation between the different types of mutations at the genes of interest. Following initial assay optimization, the assay was integrated into a droplet magnetofluidic cartridge used in a portable platform to integrate automated sample extraction, PCR amplification, and detection. Lastly, we demonstrated that the integrated assay and droplet magnetofluidic platform could detect MG and antibiotic resistance-associated mutations in clinical isolates spiked into urine samples in 40 min.
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Affiliation(s)
- Fan-En Chen
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, Maryland 21218, United States
| | - Jonathan Wang
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, Maryland 21218, United States
| | - Anju Haridas Nambiar
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, Maryland 21218, United States
| | - Justin Hardick
- Division of Infectious Diseases, Johns Hopkins University School of Medicine, Baltimore, Maryland 21218, United States
| | - Johan Melendez
- Division of Infectious Diseases, Johns Hopkins University School of Medicine, Baltimore, Maryland 21218, United States
| | - Alexander Y Trick
- Department of Mechanical Engineering, Johns Hopkins University, Baltimore, Maryland 21218, United States
| | - Tza-Huei Wang
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, Maryland 21218, United States
- Department of Mechanical Engineering, Johns Hopkins University, Baltimore, Maryland 21218, United States
- Institute for NanoBioTechnology, Johns Hopkins University, Baltimore, Maryland 21218, United States
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Kim K, Choi YM, Kim DH, Jang J, Choe WH, Kim BJ. Locked nucleic acid real-time polymerase chain reaction method identifying two polymorphisms of hepatitis B virus genotype C2 infections, rt269L and rt269I. World J Gastroenterol 2023; 29:1721-1734. [PMID: 37077521 PMCID: PMC10107212 DOI: 10.3748/wjg.v29.i11.1721] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Revised: 01/13/2023] [Accepted: 02/27/2023] [Indexed: 03/17/2023] Open
Abstract
BACKGROUND The presence of two distinct hepatitis B virus (HBV) Pol RT polymorphisms, rt269L and rt269I, could contribute to the unique clinical or virological phenotype of HBV genotype C2. Therefore, a simple and sensitive method capable of identifying both types in chronic hepatitis B (CHB) patients infected with genotype C2 should be developed.
AIM To develop a novel simple and sensitive locked nucleic acid (LNA)-real time-polymerase chain reaction (RT-PCR) method capable of identifying two rt269 types in CHB genotype C2 patients.
METHODS We designed proper primer and probe sets for LNA-RT-PCR for the separation of rt269 types. Using synthesized DNAs of the wild type and variant forms, melting temperature analysis, detection sensitivity, and endpoint genotyping for LNA-RT-PCR were performed. The developed LNA-RT-PCR method was applied to a total of 94 CHB patients of genotype C2 for the identification of two rt269 polymorphisms, and these results were compared with those obtained by a direct sequencing protocol.
RESULTS The LNA-RT-PCR method could identify two rt269L and rt269I polymorphisms of three genotypes, two rt269L types [‘L1’ (WT) and ‘L2’] and one rt269I type (‘I’) in single (63 samples, 72.4%) or mixed forms (24 samples, 27.6%) in 87 (92.6% sensitivity) of 94 samples from Korean CHB patients. When the results were compared with those obtained by the direct sequencing protocol, the LNA-RT-PCR method showed the same results in all but one of 87 positive detected samples (98.9% specificity).
CONCLUSION The newly developed LNA-RT-PCR method could identify two rt269 polymorphisms, rt269L and rt269I, in CHB patients with genotype C2 infections. This method could be effectively used for the understanding of disease progression in genotype C2 endemic areas.
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Affiliation(s)
- Kijeong Kim
- Department of Microbiology, College of Medicine, Chung-Ang University, Seoul 06974, South Korea
| | - Yu-Min Choi
- Department of Microbiology and Immunology, College of Medicine, Seoul National University, Seoul 03080, South Korea
| | - Dong Hyun Kim
- Department of Microbiology and Immunology, College of Medicine, Seoul National University, Seoul 03080, South Korea
| | - Junghwa Jang
- Department of Microbiology and Immunology, College of Medicine, Seoul National University, Seoul 03080, South Korea
| | - Won Hyeok Choe
- Department of Internal Medicine, Konkuk University School of Medicine, Seoul 05030, South Korea
| | - Bum-Joon Kim
- Department of Microbiology and Immunology, College of Medicine, Seoul National University, Seoul 03080, South Korea
- Department of Biomedical Sciences, College of Medicine, Seoul National University, Seoul 03080, South Korea
- Liver Research Institute, College of Medicine, Seoul National University, Seoul 03080, South Korea
- Seoul National University Medical Research Center, Seoul 03080, South Korea
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Jiménez-Montenegro L, Mendizabal JA, Alfonso L, Azparren L, Urrutia O. Development of a duplex qPCR assay with locked nucleic acid probes for A, B and E kappa-casein variants detection. Sci Rep 2022; 12:16387. [PMID: 36180500 PMCID: PMC9525573 DOI: 10.1038/s41598-022-20586-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Accepted: 09/15/2022] [Indexed: 11/09/2022] Open
Abstract
Milk proteins determine important milk technological characteristics. Among caseins, Ƙ-casein has been correlated with fat and protein content and cheese yield. Fourteen Ƙ-caseins variants have been described but the alleles A, B and E are the most important ones due to their frequency and/or influence on the technological aptitudes of milk. Therefore, in the present study two different duplex qPCR assays with locked nucleic acid probes (for positions 13104 and 13124 of the Ƙ-casein gene) were developed for the detection of A, B and E variants. Firstly, DNA isolation method from milk somatic cells and hair was optimised. The developed 13124-qPCR assay showed an increased sensitivity reaching up to 6.7 copies DNA copies/reaction at a 95% confidence level with A, B and E alleles reference samples. The 13104-qPCR assay reached up to 6.7 DNA copies/reaction for A allele reference sample and 67 DNA copies/reaction for B and E samples. Intra-assay variation results were below 6%. Applicability was determined using DNA samples from animals with known genotype for Ƙ-casein (AA, AB, BB, BE, AE, EE) and both assays were able to discriminate among the six genotypes with 100% accuracy. Thus, this qPCR method represents a sensitive and rapid option for the detection of Ƙ-casein alleles in both hair and milk samples.
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Affiliation(s)
- L Jiménez-Montenegro
- IS-FOOD, School of Agricultural Engineering and Biosciences, Public University of Navarre (UPNA), Campus de Arrosadia, 31006, Pamplona, Spain
| | - J A Mendizabal
- IS-FOOD, School of Agricultural Engineering and Biosciences, Public University of Navarre (UPNA), Campus de Arrosadia, 31006, Pamplona, Spain
| | - L Alfonso
- IS-FOOD, School of Agricultural Engineering and Biosciences, Public University of Navarre (UPNA), Campus de Arrosadia, 31006, Pamplona, Spain
| | - L Azparren
- IS-FOOD, School of Agricultural Engineering and Biosciences, Public University of Navarre (UPNA), Campus de Arrosadia, 31006, Pamplona, Spain
| | - O Urrutia
- IS-FOOD, School of Agricultural Engineering and Biosciences, Public University of Navarre (UPNA), Campus de Arrosadia, 31006, Pamplona, Spain.
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Durand M, Thibault P, Lévesque S, Brault A, Carignan A, Valiquette L, Martin P, Labbé S. Detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and its first variants in fourplex real-time quantitative reverse transcription-PCR assays. MICROBIAL CELL (GRAZ, AUSTRIA) 2022; 9:1-20. [PMID: 35083313 PMCID: PMC8717086 DOI: 10.15698/mic2022.01.767] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Revised: 11/17/2021] [Accepted: 11/22/2021] [Indexed: 11/23/2022]
Abstract
The early diagnosis of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections is required to identify and isolate contagious patients to prevent further transmission of SARS-CoV-2. In this study, we present a multitarget real-time TaqMan reverse transcription PCR (rRT-PCR) assay for the quantitative detection of SARS-CoV-2 and some of its circulating variants harboring mutations that give the virus a selective advantage. Seven different primer-probe sets that included probes containing locked nucleic acid (LNA) nucleotides were designed to amplify specific wild-type and mutant sequences in Orf1ab, Envelope (E), Spike (S), and Nucleocapsid (N) genes. Furthermore, a newly developed primer-probe set targeted human β2-microglobulin (B2M) as a highly sensitive internal control for RT efficacy. All singleplex and fourplex assays detected ≤ 14 copies/reaction of quantified synthetic RNA transcripts, with a linear amplification range of nine logarithmic orders. Primer-probe sets for detection of SARS-CoV-2 exhibited no false-positive amplifications with other common respiratory pathogens, including human coronaviruses NL63, 229E, OC43, and HKU-1. Fourplex assays were evaluated using 160 clinical samples positive for SARS-CoV-2. Results showed that SARS-CoV-2 viral RNA was detected in all samples, including viral strains harboring mutations in the Spike coding sequence that became dominant in the pandemic. Given the emergence of SARS-CoV-2 variants and their rapid spread in some populations, fourplex rRT-PCR assay containing four primer-probe sets represents a reliable approach to allow quicker detection of circulating relevant variants in a single reaction.
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Affiliation(s)
- Mathieu Durand
- Plateforme RNomique et de Génomique Fonctionnelle, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Philippe Thibault
- Plateforme RNomique et de Génomique Fonctionnelle, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Simon Lévesque
- Département de Microbiologie et d'Infectiologie, Faculté de médecine et des sciences de la santé, Université de Sherbrooke, Sherbrooke, QC, Canada.,Laboratoire de Microbiologie, Centre Intégré Universitaire de Santé et de Services Sociaux (CIUSSS) de l'Estrie, Centre Hospitalier Universitaire de Sherbrooke (CHUS), Sherbrooke, QC, Canada
| | - Ariane Brault
- Département de Biochimie et de Génomique Fonctionnelle, Faculté de médecine et des sciences de la santé, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Alex Carignan
- Département de Microbiologie et d'Infectiologie, Faculté de médecine et des sciences de la santé, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Louis Valiquette
- Département de Microbiologie et d'Infectiologie, Faculté de médecine et des sciences de la santé, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Philippe Martin
- Département de Microbiologie et d'Infectiologie, Faculté de médecine et des sciences de la santé, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Simon Labbé
- Département de Biochimie et de Génomique Fonctionnelle, Faculté de médecine et des sciences de la santé, Université de Sherbrooke, Sherbrooke, QC, Canada
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9
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Giglioti R, Hiromi Okino C, Tainá Azevedo B, Gutmanis G, Morita Katiki L, Cristina de Sena Oliveira M, Eugênio Vercesi Filho A. Novel LNA probe-based assay for the A1 and A2 identification of β-casein gene in milk samples. FOOD CHEMISTRY: MOLECULAR SCIENCES 2021; 3:100055. [PMID: 35415647 PMCID: PMC8991969 DOI: 10.1016/j.fochms.2021.100055] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 11/19/2021] [Accepted: 11/25/2021] [Indexed: 11/17/2022]
Abstract
A novel LNA probe-based qPCR allowed the detection of A1 and A2 alleles from β -casein gene in bovine samples. 100% of agreement between results obtained by rHamp and LNA qPCR assays. The limit of detection of A1 in A2 samples was 1% or 7.5 DNA copies. This method is a highly sensitive and specific tool for detecting A1 and A2 alleles directly in milk.
The rising consumption of A2 milk and its derivatives in recent years has garnered attention from both consumers and producers, mainly due its possible health benefits, such as enhanced digestion and easier absorption. Thus, a novel real-time PCR using a combination of locked nucleic acid modified (LNA) conjugated probes was developed to genotype A1 and A2 alleles of β-casein gene (CSN2) and to detect and quantify the A1 presence in A2 samples. The limit of detection for each probe (A1 and A2) was evaluated using decreasing serial dilutions. Besides, the sensitivity of A1 allele detection in the A2 samples was also tested. The limits of detection of A1 and A2 alleles were 6 copies, while for A1 allele detection in A2 samples was 7.5 copies (1%). The LNA-probe based method was found to be rapid, robust, highly sensitive, cost effective, and can be employed as screening test to certificate the A2 dairy products.
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Affiliation(s)
- Rodrigo Giglioti
- Instituto de Zootecnia, Rua Heitor Penteado, n. 56, Nova Odessa, São Paulo 13380-011, Brazil
- Corresponding author.
| | | | - Bianca Tainá Azevedo
- Instituto de Zootecnia, Rua Heitor Penteado, n. 56, Nova Odessa, São Paulo 13380-011, Brazil
| | - Gunta Gutmanis
- Instituto de Zootecnia, Rua Heitor Penteado, n. 56, Nova Odessa, São Paulo 13380-011, Brazil
| | - Luciana Morita Katiki
- Instituto de Zootecnia, Rua Heitor Penteado, n. 56, Nova Odessa, São Paulo 13380-011, Brazil
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10
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Fujita K, Nakayama M, Sata M, Nagai Y, Hisata S, Mato N, Suzuki T, Bando M, Hizawa N, Hagiwara K. Highly sensitive detection of driver mutations from cytological samples and cfDNA in lung cancer. Cancer Med 2021; 10:8595-8603. [PMID: 34617674 PMCID: PMC8633228 DOI: 10.1002/cam4.4330] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2021] [Revised: 08/28/2021] [Accepted: 08/29/2021] [Indexed: 11/09/2022] Open
Abstract
BACKGROUND Bronchoscopy is a minimally invasive procedure for establishing the diagnosis of lung cancer. It sometimes fails to obtain tissue samples but readily collects cytological samples. METHODS We developed PNA-LNA dual-PCR (PLDP), which amplified mutant sequences by a high-fidelity DNA polymerase in the presence of a peptide nucleic acid (PNA) oligomer having a wild-type sequence. Mutations are detected either by locked nucleic acid (LNA) probes for quick detection of a limited number of mutations, which are EGFR, KRAS, and BRAF mutations in the current study, or by direct sequencing for a comprehensive screening. In a total of 233 lung cancer samples, the results for cytological samples by PLDP were compared with those for tissue samples by cobas® EGFR mutation test (cobas) or by the PNA-LNA PCR clamp method (P-LPC). Moreover, the performance of PLDP using cell-free DNA (cfDNA) was investigated. RESULTS Peptide nucleic acid-LNA dual-PCR was able to detect each synthesized mutant sequence with high sensitivity. PLDP detected EGFR mutations in 80 out of 149 clinical samples, while the cobas or the P-LPC detected in 66 matched. The correctness of PLDP was confirmed both by clinical response and by the results of sequencing using a next-generation sequencer. PLDP detected mutations from cfDNA in approximately 70% of patients who harbors mutations in the tumor. CONCLUSIONS Peptide nucleic acid-LNA dual-PCR exhibited an excellent performance, even using cytological samples. PLDP is applicable for the investigation of cfDNA. The combination of bronchoscopy and PLDP is attractive and will expand the utility of bronchoscopy in clinical practice.
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Affiliation(s)
- Kazutaka Fujita
- Department of Pulmonary Medicine, University of Tsukuba, Tsukuba, Ibaraki, Japan.,Division of Pulmonary Medicine, Department of Internal Medicine, Jichi Medical University, Shimotsuke-shi, Tochigi, Japan
| | - Masayuki Nakayama
- Division of Pulmonary Medicine, Department of Internal Medicine, Jichi Medical University, Shimotsuke-shi, Tochigi, Japan
| | - Masafumi Sata
- Division of Pulmonary Medicine, Department of Internal Medicine, Jichi Medical University, Shimotsuke-shi, Tochigi, Japan
| | - Yoshiaki Nagai
- Division of Pulmonary Medicine, Department of Internal Medicine, Jichi Medical University, Shimotsuke-shi, Tochigi, Japan
| | - Shu Hisata
- Division of Pulmonary Medicine, Department of Internal Medicine, Jichi Medical University, Shimotsuke-shi, Tochigi, Japan
| | - Naoko Mato
- Division of Pulmonary Medicine, Department of Internal Medicine, Jichi Medical University, Shimotsuke-shi, Tochigi, Japan
| | - Takuji Suzuki
- Division of Pulmonary Medicine, Department of Internal Medicine, Jichi Medical University, Shimotsuke-shi, Tochigi, Japan
| | - Masashi Bando
- Division of Pulmonary Medicine, Department of Internal Medicine, Jichi Medical University, Shimotsuke-shi, Tochigi, Japan
| | - Nobuyuki Hizawa
- Department of Pulmonary Medicine, University of Tsukuba, Tsukuba, Ibaraki, Japan
| | - Koichi Hagiwara
- Division of Pulmonary Medicine, Department of Internal Medicine, Jichi Medical University, Shimotsuke-shi, Tochigi, Japan
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11
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Higgins O, Smith TJ. 3' Tth Endonuclease Cleavage Polymerase Chain Reaction (3TEC-PCR) Technology for Single-Base-Specific Multiplex Pathogen Detection using a Two-Oligonucleotide System. Int J Mol Sci 2021; 22:6061. [PMID: 34199760 PMCID: PMC8199996 DOI: 10.3390/ijms22116061] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2021] [Revised: 05/28/2021] [Accepted: 06/01/2021] [Indexed: 11/21/2022] Open
Abstract
Polymerase chain reaction (PCR) is the standard in nucleic acid amplification technology for infectious disease pathogen detection and has been the primary diagnostic tool employed during the global COVID-19 pandemic. Various PCR technology adaptations, typically using two-oligonucleotide dye-binding methods or three-oligonucleotide hydrolysis probe systems, enable real-time multiplex target detection or single-base specificity for the identification of single-nucleotide polymorphisms (SNPs). A small number of two-oligonucleotide PCR systems facilitating both multiplex detection and SNP identification have been reported; however, these methods often have limitations in terms of target specificity, production of variable or false-positive results, and the requirement for extensive optimisation or post-amplification analysis. This study introduces 3' Tth endonuclease cleavage PCR (3TEC-PCR), a two-oligonucleotide PCR system incorporating a modified primer/probe and a thermostable cleavage enzyme, Tth endonuclease IV, for real-time multiplex detection and SNP identification. Complete analytical specificity, low limits of detection, single-base specificity, and simultaneous multiple target detection have been demonstrated in this study using 3TEC-PCR to identify bacterial meningitis associated pathogens. This is the first report of a two-oligonucleotide, real-time multiplex PCR technology with single-base specificity using Tth endonuclease IV.
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Affiliation(s)
- Owen Higgins
- Molecular Diagnostics Research Group, School of Natural Sciences, National University of Ireland, Galway, Ireland;
- Centre for One Health, Ryan Institute, National University of Ireland, Galway, Ireland
| | - Terry J. Smith
- Molecular Diagnostics Research Group, School of Natural Sciences, National University of Ireland, Galway, Ireland;
- Centre for One Health, Ryan Institute, National University of Ireland, Galway, Ireland
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12
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Song J, Kim S, Kim HY, Hur KH, Kim Y, Park HG. A novel method to detect mutation in DNA by utilizing exponential amplification reaction triggered by the CRISPR-Cas9 system. NANOSCALE 2021; 13:7193-7201. [PMID: 33720266 DOI: 10.1039/d1nr00438g] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
We, herein, describe a novel method to detect mutation in DNA by utilizing exponential amplification reaction (EXPAR) triggered by clustered regularly interspaced short palindromic repeats (CRISPR)-Cas9, called CRISPR-EXPAR. The CRISPR system consisting of two Cas9/sgRNA complexes was designed to cut out a specific mutation region within the target DNA, which would consequently promote EXPAR by continuously repeated extension and nicking reactions. As a consequence, a large number of final EXPAR products, which can be monitored through duplex-specific fluorescent staining, are produced. Based on this design principle, we successfully identified a model target mutation within the human epidermal growth factor receptor 2 (HER2) gene down to 437 aM with excellent specificity. The practical capability of this method was verified by reliably identifying the target mutation directly from the genomic DNA (gDNA) extracted from the lung cancer cell line, NCI-H1781 (H1781), and its universal applicability was further confirmed by identifying another EFGF L858R mutation. This technique could serve as a new isothermal platform to identify various mutations by rationally redesigning single guide RNA (sgRNA) according to the target mutation site.
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Affiliation(s)
- Jayeon Song
- Department of Chemical and Biomolecular Engineering (BK 21+ program), KAIST, Daehak-ro 291, Yuseong-gu, Daejeon 34141, Republic of Korea.
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13
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Natoli ME, Chang MM, Kundrod KA, Coole JB, Airewele GE, Tubman VN, Richards-Kortum RR. Allele-Specific Recombinase Polymerase Amplification to Detect Sickle Cell Disease in Low-Resource Settings. Anal Chem 2021; 93:4832-4840. [PMID: 33689292 PMCID: PMC7992048 DOI: 10.1021/acs.analchem.0c04191] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Sickle cell disease (SCD) is a group of common, life-threatening disorders caused by a point mutation in the β globin gene. Early diagnosis through newborn and early childhood screening, parental education, and preventive treatments are known to reduce mortality. However, the cost and complexity of conventional diagnostic methods limit the feasibility of early diagnosis for SCD in resource-limited areas worldwide. Although several point-of-care tests are commercially available, most are antibody-based tests, which cannot be used in patients who have recently received a blood transfusion. Here, we describe the development of a rapid, low-cost nucleic acid test that uses real-time fluorescence to detect the point mutation encoding hemoglobin S (HbS) in one round of isothermal recombinase polymerase amplification (RPA). When tested with a set of clinical samples from SCD patients and healthy volunteers, our assay demonstrated 100% sensitivity for both the βA globin and βS globin alleles and 94.7 and 97.1% specificities for the βA globin allele and βS globin allele, respectively (n = 91). Finally, we demonstrate proof-of-concept sample-to-answer genotyping of genomic DNA from capillary blood using an alkaline lysis procedure and direct input of diluted lysate into RPA. The workflow is performed in <30 min at a cost of <$5 USD on a commercially available benchtop fluorimeter and an open-source miniature fluorimeter. This study demonstrates the potential utility of a rapid, sample-to-answer nucleic acid test for SCD that may be implemented near the point of care and could be adapted to other disease-causing point mutations in genomic DNA.
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Affiliation(s)
- Mary E Natoli
- Department of Bioengineering, Rice University, Houston, Texas 77005, United States
| | - Megan M Chang
- Department of Bioengineering, Rice University, Houston, Texas 77005, United States
| | - Kathryn A Kundrod
- Department of Bioengineering, Rice University, Houston, Texas 77005, United States
| | - Jackson B Coole
- Department of Bioengineering, Rice University, Houston, Texas 77005, United States
| | - Gladstone E Airewele
- Texas Children's Cancer and Hematology Centers, Houston, Texas 77030, United States.,Baylor College of Medicine, Houston, Texas 77030, United States
| | - Venée N Tubman
- Texas Children's Cancer and Hematology Centers, Houston, Texas 77030, United States.,Baylor College of Medicine, Houston, Texas 77030, United States
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14
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Zhang K, Deng R, Gao H, Teng X, Li J. Lighting up single-nucleotide variation in situ in single cells and tissues. Chem Soc Rev 2020; 49:1932-1954. [PMID: 32108196 DOI: 10.1039/c9cs00438f] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The ability to 'see' genetic information directly in single cells can provide invaluable insights into complex biological systems. In this review, we discuss recent advances of in situ imaging technologies for visualizing the subtlest sequence alteration, single-nucleotide variation (SNV), at single-cell level. The mechanism of recently developed methods for SNV discrimination are summarized in detail. With recent developments, single-cell SNV imaging methods have opened a new door for studying the heterogenous and stochastic genetic information in individual cells. Furthermore, SNV imaging can be used on morphologically preserved tissue, which can provide information on histological context for gene expression profiling in basic research and genetic diagnosis. Moreover, the ability to visualize SNVs in situ can be further developed into in situ sequencing technology. We expect this review to inspire more research work into in situ SNV imaging technologies for investigating cellular phenotypes and gene regulation at single-nucleotide resolution, and developing new clinical and biomedical applications.
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Affiliation(s)
- Kaixiang Zhang
- Department of Chemistry, Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology, Beijing Key Laboratory for Microanalytical Methods and Instrumentation, Tsinghua University, Beijing 100084, China. and School of Pharmaceutical Sciences, Zhengzhou University, Zhengzhou 450001, China
| | - Ruijie Deng
- Department of Chemistry, Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology, Beijing Key Laboratory for Microanalytical Methods and Instrumentation, Tsinghua University, Beijing 100084, China.
| | - Hua Gao
- Department of Chemistry, Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology, Beijing Key Laboratory for Microanalytical Methods and Instrumentation, Tsinghua University, Beijing 100084, China. and Department of Pathogeny Biology, Medical College, Zhengzhou University, Zhengzhou 450001, China
| | - Xucong Teng
- Department of Chemistry, Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology, Beijing Key Laboratory for Microanalytical Methods and Instrumentation, Tsinghua University, Beijing 100084, China.
| | - Jinghong Li
- Department of Chemistry, Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology, Beijing Key Laboratory for Microanalytical Methods and Instrumentation, Tsinghua University, Beijing 100084, China.
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15
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DNA-based techniques for seafood species authentication. ADVANCES IN FOOD AND NUTRITION RESEARCH 2020; 95:207-255. [PMID: 33745513 DOI: 10.1016/bs.afnr.2020.09.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
Abstract
Global trade of seafood has increased in the last decade, leading to significant concerns associated with seafood fraud. Seafood fraud involves the intentional misrepresentation of fish or shellfish for the purpose of economic gain and includes acts such as species substitution, illegal transshipment, overtreatment/short weighting, and mislabeling country of origin or production method. These fraudulent acts have had economic, environmental, and public health consequences on a global level. DNA-based techniques for seafood authentication are utilized by regulatory agencies and can be employed as part of a food fraud risk mitigation plan. This chapter will focus specifically on the use of DNA-based methods for the detection of seafood species substitution. Various methods have been developed for DNA-based species identification of seafood, including polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP), species-specific PCR, real-time PCR, Sanger sequencing, microarrays, and high-resolution melting (HRM). Emerging techniques for seafood authentication include droplet digital PCR, isothermal amplification, PCR-enzyme-linked immunosorbent assay (ELISA), and high-throughput or next-generation sequencing. Some of these DNA-based methods target specific species, such as real-time PCR and droplet digital PCR, while other methods allow for simultaneous differentiation of a wide range of fish species, including Sanger sequencing and high-throughput sequencing. This chapter will begin with an introduction on seafood fraud and species substitution, followed by an analysis of the main DNA-based authentication methods and emerging techniques for species identification.
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16
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Mitake M, Hirano S, Kishino T. Imprinting analysis by droplet digital PCR coupled with locked nucleic acid TaqMan probes. Epigenetics 2020; 16:729-740. [PMID: 32970510 DOI: 10.1080/15592294.2020.1823160] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
Abstract
Imprinted genes are differentially expressed in a parent-of-origin-specific manner. Parental origin of the alleles is discriminated by intragenic DNA polymorphisms. Comparisons of parental allelic expression have been analysed by semiquantitative RT-PCR. Here, we developed a novel quantitative method for allelic expression of the imprinted gene Ube3a, which inactivation and mutations cause Angelman syndrome and predominantly expressed by the maternal allele in neuronal tissues. In this method, cDNA was amplified by droplet digital PCR (ddPCR) coupled with allele-specific locked nucleic acid (LNA) TaqMan probes, which labelled by FAM and HEX were designed to detect the SNPs in the target regions. ddPCR assay demonstrated that the sense transcript of Ube3a was equally expressed from both parental alleles in adult tissues except neuronal tissues, where Ube3a expression from the paternal allele was about 10 to 14% of total Ube3a expression in adult brain, and 20% in spinal cord. The antisense transcript of Ube3a was expressed at 60% to 70% of the sense transcript of Ube3a in adult brain. Changes in the Ube3a transcripts during postnatal brain development were also evaluated by ddPCR. The ddPCR method is far more reliable and simpler to use than semiquantitative PCR to analyse skewed or faint allelic expression of imprinted genes.
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Affiliation(s)
- Maiko Mitake
- Division of Functional Genomics, Centre for Frontier Life Sciences, Nagasaki University, Nagasaki, Japan
| | - Shiori Hirano
- Division of Functional Genomics, Centre for Frontier Life Sciences, Nagasaki University, Nagasaki, Japan
| | - Tatsuya Kishino
- Division of Functional Genomics, Centre for Frontier Life Sciences, Nagasaki University, Nagasaki, Japan
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17
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Abstract
Quantitative real-time PCR (qPCR) is a widely adopted technique used for scientific, clinical, diagnostic, or quality control purposes. One of the main applications of qPCR is gene expression analysis, although mutation detection, genotyping, DNA detection, and quantification (from pathogens or genetically modified organisms) are also investigated using this technique.Although nonspecific detection based on DNA-binding dyes (including SYBR Green I) offers versatility in qPCR assays, detection of the PCR product using fluorescent probes confers higher specificity and sensitivity to assays, justifying the use of fluorescent probes as a detection method.This chapter seeks to propose a procedure for the design of qPCR assays using fluorescent hydrolysis probe technology. Particular attention will be paid to explaining the steps necessary to ensure the specificity of the oligonucleotides used as primers or fluorescent probes.
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Affiliation(s)
- Florent Busi
- Unité de Biologie Fonctionnelle et Adaptative, Université de Paris, CNRS UMR 8251, Paris, France.
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18
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Rapid Subtyping and Pathotyping of Avian Influenza Virus using Chip-based RT-PCR. BIOCHIP JOURNAL 2019. [DOI: 10.1007/s13206-019-3405-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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19
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Designed phosphate-methylated oligonucleotides as PCR primers for SNP discrimination. Anal Bioanal Chem 2019; 411:3871-3880. [PMID: 31209551 DOI: 10.1007/s00216-019-01865-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Revised: 03/18/2019] [Accepted: 04/23/2019] [Indexed: 11/25/2022]
Abstract
Polymerase chain reaction (PCR) is a powerful technique for the detection and quantification of nucleic acids and has enormous applications to research in molecular biology. Certain inherited diseases, caused by single nucleotide mutations, however, are difficult to identify by PCR, using DNA primers and probes, in a situation where a false diagnosis may lead to incorrect or delayed treatment. With the aim of enhancing the specificity of PCR, we used novel chemically synthesized oligonucleotides containing site-specific methyl phosphotriester (MPTE) inter-nucleoside linkage(s) as primers and probes. The methyl phosphotriester linkages carry no charge, so the reduction in the electrostatic repulsion of an MPTE-DNA/DNA duplex shows stronger hybridization affinity compared to a DNA/DNA duplex. However, the electrosteric effects introduced by the methyl group may result in instability of the double-stranded DNA (dsDNA) formed. With the use of specific MPTE modification sites and optimization of the number of MPTE modifications, greater delta melting temperature (ΔTm) may be obtained, in concert with adjustment of PCR operating conditions, especially with respect to the annealing temperature, to achieve more discriminatory results between the target template and the perfectly matched primer and the mismatched primer. In single nucleotide polymorphism (SNP) genotyping, the results demonstrated that MPTE-modified probes can improve specificity. In summary, MPTE-modified oligonucleotides are a promising DNA analog applied to PCR primers and probes to enhance the specificity and to provide more precise detection results for various applications, such as for genetic diagnosis. In summary, two common DNA polymerases we tested could successfully recognize the MPTE-modified primers and probes. Under the optimal operating conditions, MPTE modification has the ability to improve the discrimination of single nucleotide polymorphism by increasing the ΔTm of the perfect match and mismatch sequences and to provide more precise detection results for various applications, such as genetic diagnosis.
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20
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Verrez-Bagnis V, Sotelo CG, Mendes R, Silva H, Kappel K, Schröder U. Methods for Seafood Authenticity Testing in Europe. BIOACTIVE MOLECULES IN FOOD 2019. [DOI: 10.1007/978-3-319-78030-6_69] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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21
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Ishige T, Satoh M, Itoga S, Nishimura M, Matsushita K, Nomura F. High-throughput genotyping of GC (vitamin D-binding protein) by melting analysis with locked nucleic acid-incorporating dual hybridization probe for improving mismatch discrimination. Clin Chim Acta 2018; 487:126-132. [PMID: 30253141 DOI: 10.1016/j.cca.2018.09.034] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Revised: 09/11/2018] [Accepted: 09/22/2018] [Indexed: 11/25/2022]
Affiliation(s)
- Takayuki Ishige
- Division of Laboratory Medicine, Chiba University Hospital, Chiba, Japan.
| | - Mamoru Satoh
- Division of Clinical Mass Spectrometry, Chiba University Hospital, Chiba, Japan
| | - Sakae Itoga
- Division of Laboratory Medicine, Chiba University Hospital, Chiba, Japan
| | - Motoi Nishimura
- Division of Laboratory Medicine, Chiba University Hospital, Chiba, Japan
| | | | - Fumio Nomura
- Division of Clinical Mass Spectrometry, Chiba University Hospital, Chiba, Japan
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22
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Nakagaki A, Hirano S, Urakawa A, Mitake M, Kishino T. Transgenic mice with a tandem duplication of the Necdin gene overexpress Necdin. Mamm Genome 2018; 29:680-689. [PMID: 30225647 DOI: 10.1007/s00335-018-9784-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2018] [Accepted: 09/12/2018] [Indexed: 01/13/2023]
Abstract
Necdin (Ndn) transgenic (Tg) mice were generated with a bacterial artificial chromosome (BAC) clone. Droplet digital PCR (ddPCR) and inverse PCR methods revealed that the transgene consisted of four fragments with a total length of 171 kb. Two of these fragments were tandem tail-to-tail duplicates of 77 kb and 37 kb that both contained a Ndn gene. The transgene was inserted in chromosome 15qD1. Ndn is a paternally expressed imprinted gene; however, the total expression level of Ndn in hemizygous Tg mice was approximately twofold higher than that in wild-type mice. ddPCR assays with locked nucleic acid (LNA) TaqMan probes revealed that transgenic Ndn expression was almost equal to endogenous Ndn expression, despite there being two copies of the Ndn gene in the transgene, indicating an interaction between the transcriptional regulation of endogenous Ndn and the transgene. ddPCR assays with LNA TaqMan probes were also applied for imprinting analysis to confirm exclusive paternal expression in tissues with low Ndn expression. This is the first report of a Tg mouse with a tandem duplication of a Ndn transgene and Ndn overexpression, which will be useful for the in vivo study of Ndn overexpression and for rescue experiments of the neonatal lethality seen in the Ndn knockout mouse.
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Affiliation(s)
- Ayumi Nakagaki
- Division of Functional Genomics, Center for Frontier Life Sciences, Nagasaki University, Sakamoto 1-12-4, Nagasaki, 852-8523, Japan
| | - Shiori Hirano
- Division of Functional Genomics, Center for Frontier Life Sciences, Nagasaki University, Sakamoto 1-12-4, Nagasaki, 852-8523, Japan
| | - Asuka Urakawa
- Division of Functional Genomics, Center for Frontier Life Sciences, Nagasaki University, Sakamoto 1-12-4, Nagasaki, 852-8523, Japan
| | - Maiko Mitake
- Division of Functional Genomics, Center for Frontier Life Sciences, Nagasaki University, Sakamoto 1-12-4, Nagasaki, 852-8523, Japan
| | - Tatsuya Kishino
- Division of Functional Genomics, Center for Frontier Life Sciences, Nagasaki University, Sakamoto 1-12-4, Nagasaki, 852-8523, Japan.
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Development of a Real-Time Reverse Transcription-PCR Assay for Global Differentiation of Yellow Fever Virus Vaccine-Related Adverse Events from Natural Infections. J Clin Microbiol 2018; 56:JCM.00323-18. [PMID: 29643198 DOI: 10.1128/jcm.00323-18] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2018] [Accepted: 04/05/2018] [Indexed: 11/20/2022] Open
Abstract
Yellow fever (YF) is a reemerging public health threat, with frequent outbreaks prompting large vaccination campaigns in regions of endemicity in Africa and South America. Specific detection of vaccine-related adverse events is resource-intensive, time-consuming, and difficult to achieve during an outbreak. To address this, we have developed a highly transferable rapid yellow fever virus (YFV) vaccine-specific real-time reverse transcription-PCR (RT-PCR) assay that distinguishes vaccine from wild-type lineages. The assay utilizes a specific hydrolysis probe that includes locked nucleic acids to enhance specific discrimination of the YFV17D vaccine strain genome. Promisingly, sensitivity and specificity analyses reveal this assay to be highly specific to vaccine strain(s) when tested on clinical samples and YFV cell culture isolates of global origin. Taken together, our data suggest the utility of this assay for use in laboratories of varied capacity for the identification and differentiation of vaccine-related adverse events from wild-type infections of both African and South American origin.
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24
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Locked Nucleic Acid Technology for Highly Sensitive Detection of Somatic Mutations in Cancer. Adv Clin Chem 2017; 83:53-72. [PMID: 29304903 DOI: 10.1016/bs.acc.2017.10.002] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The molecular diagnosis of the cancer mutational status is essential for modern clinical laboratory medicine. Mutations in EGFR, KRAS, BRAF, and PIK3CA genes are widely analyzed in solid tumors such as lung cancer, colorectal cancer, breast cancer, and melanoma. The allele-specific polymerase chain reaction, high-resolution melting, and Sanger sequencing are used for detecting and identifying gene mutations in many clinical laboratories. The locked nucleic acid (LNA) is a class of nucleic acid analogs that contain a methylene bridge connecting the 2' oxygen and 4' carbon in the ribose moiety. This methylene bridge locks the ribose group into a C3'-endo conformation. LNA, including an oligonucleotide, increases the thermal stability of hybrid strands. The use of LNA technology in molecular diagnostic methods improves the specificity and sensitivity of assays. This review describes routinely analyzed mutations and molecular diagnostic methods used in the clinical laboratory along with the performance improvement of mutational analysis with LNA.
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PCR-Based Detection Methods for Single-Nucleotide Polymorphism or Mutation: Real-Time PCR and Its Substantial Contribution Toward Technological Refinement. Adv Clin Chem 2017; 80:45-72. [PMID: 28431642 DOI: 10.1016/bs.acc.2016.11.002] [Citation(s) in RCA: 77] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Single-nucleotide polymorphisms (SNPs) and single-nucleotide mutations result from the substitution of only a single base. The SNP or mutation can be relevant to disease susceptibility, pathogenesis of disease, and efficacy of specific drugs. It is important to detect SNPs or mutations clinically. Methods to distinguish/detect SNPs or mutations should be highly specific and sensitive. In this regard, polymerase chain reaction (PCR) has provided the necessary analytical performance for many molecular analyses. PCR-based methods for SNP/mutation detection are broadly categorized into two types-(1) polymorphic or mutant allele-directed specific analysis using primers matched with substituted nucleotide or using oligonucleotides to block or clamp the nontargeted template, and (2) melting curve analysis, which is combined with the real-time PCR techniques using hydrolysis probes, hybridization probes, or double-stranded DNA-binding fluorescent dyes. Innovative and novel approaches as well as technical improvements have made SNP- or mutation-detection methods increasingly more sophisticated. These advances include DNA/RNA preparation and subsequent amplification steps, and miniaturization of PCR instruments such that testing may be performed with relative ease in clinical laboratories or as a point-of-care test in clinical settings.
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Piezoelectric Plate Sensor (PEPS) for Analysis of Specific KRAS Point Mutations at Low Copy Number in Urine Without DNA Isolation or Amplification. Methods Mol Biol 2017; 1572:327-348. [PMID: 28299698 DOI: 10.1007/978-1-4939-6911-1_22] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
Abstract
We have examined in situ detection of single-nucleotide KRAS mutations in urine using a (Pb(Mg1/3Nb2/3)O3)0.65(PbTiO3)0.35 (PMN-PT) piezoelectric plate sensor (PEPS) coated with a 17-nucleotide (nt) locked nucleic acid (LNA) probe DNA complementary to the KRAS mutation without DNA isolation and amplification. In situ mutant (MT) DNA in urine in a wild type (WT) background was carried out at a flow rate of 4 mL/min and at 63 °C with the PEPS vertically situated at the center of the flow. Both the temperature and the impingement flow force discriminated the wild type. Under these conditions PEPS was shown to specifically detect KRAS MT in situ within 30 min with an analytical sensitivity of 60 copies/mL in a clinically relevant background of WT with concentrations 1000-fold greater than that of MT without DNA isolation, amplification, or labeling. For validation, detection was performed in a mixture of blue MT fluorescent reporter microspheres (FRMs) (MT FRMs) that bound to only the captured MT, and orange WT FRMs that bound to only the captured WT. The captured blue MT FRMs still outnumbered the orange WT FRMs by a factor of 4-1 even though WT was 1000-fold of MT in urine, illustrating the specificity of the point mutation detection.
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Locked Nucleic Acid Probes (LNA) for Enhanced Detection of Low-Level, Clinically Significant Mutations. Methods Mol Biol 2016; 1392:71-82. [PMID: 26843048 DOI: 10.1007/978-1-4939-3360-0_8] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
The detection of clinically significant somatic mutations present at low level in a tissue sample represents a challenge in any laboratory. While several high sensitivity methods are described, the incorporation of these new techniques in a clinical lab may be difficult if the technology is not readily available or requires major changes in the workflow of the laboratory. Techniques that are robust and easily adapted to existing laboratory protocols are highly advantageous. In this chapter we describe the use of locked nucleic acid (LNA) probes to modify existing polymerase chain reaction (PCR)-based protocols which can then be sequenced by Sanger sequencing. LNA probes are used to enhance the sensitivity of Sanger sequencing to mutation frequencies below 1 %. The method is robust and is easily incorporated for assessment of any sample with low tumor content or low mutant allele burden.
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Barefield DY, Lynch TL, Jagadeesan A, Sanagala T, Sadayappan S. High-Throughput Diagnostic Assay for a Highly Prevalent Cardiomyopathy-Associated MYBPC3 Variant. ACTA ACUST UNITED AC 2016; 7. [PMID: 27990320 PMCID: PMC5160998 DOI: 10.4172/2155-9929.1000303] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
A 25-basepair deletion variant of MYBPC3 occurs at high frequency in individuals of South Asian descent and is estimated to affect 55 million people worldwide, carrying an increased likelihood of cardiomyopathy. Since this variant is prevalent and severe in this subpopulation, quick and affordable screening to provide risk-assessment to guide treatment for these patients is critical. An RNaseH qPCR assay was developed to quickly and specifically diagnose the presence of the 25-basepair deletion variant in MYBPC3. RNAseH-blocked nucleotide primers were designed to identify the presence or absence of the wild type MYBPC3 allele or the genomic sequence containing the 25-basepair deletion. Using this assay, three blinded operators were able to accurately determine the genotype from human genomic DNA samples from blood and saliva using a qPCR thermocycler. Furthermore, positive variant subjects were examined by both electrocardiography and echocardiography for the presence of cardiomyopathy. A simple, robust assay was established, verified and validated that can be automated to detect the presence of the highly prevalent 25-basepair deletion MYBPC3 variant using both blood and saliva samples. The assay will provide quick and accurate prescreening of individuals at high risk for cardiomyopathies and allow for better clinical identification of 25-basepair deletion MYBPC3 carriers in large cohort epidemiological studies.
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Affiliation(s)
- David Y Barefield
- Department of Cell and Molecular Physiology, Loyola University, Chicago, USA; Center for Genetic Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
| | - Thomas L Lynch
- Department of Cell and Molecular Physiology, Loyola University, Chicago, USA
| | | | - Thriveni Sanagala
- Department of Cardiology and Echocardiography and Cardiographics, Loyola University, Chicago, USA
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Wei H, Zhao G, Hu T, Tang S, Jiang J, Hu B, Guan Y. Mapping the nicking efficiencies of nickase R.BbvCI for side-specific LNA-substituted substrates using rolling circle amplification. Sci Rep 2016; 6:32560. [PMID: 27582033 PMCID: PMC5007493 DOI: 10.1038/srep32560] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2016] [Accepted: 08/09/2016] [Indexed: 11/29/2022] Open
Abstract
We used a novel asymmetric cleavage analysis method based on rolling circle amplification (RCA) to determine the effects of LNA modification of substrate on the two subunits of R.BbvCI cleavage. We designed two sets of cleavage circular substrates by using two different ligation strategies and analyzed the single strand cleavage efficiency affected by different modification positions both from the cleaved strands and the uncleaved strands. Results showed that the effects of LNA on cleavage rates of modified strands and unmodified strands were both site-dependent. The Nb.BbvCI and Nt.BbvCI were affected by LNA modification in different way. Most of the modification positions showed strong inhibition of both of these two nickases cleavage. However, the modification in T3 position of bottom strand hardly affected both of the two nickases activities. The results suggested an intimated interaction between the two subunits of R.BbvCI, and the T3 position in bottom strand might be a less tight position which was hard to be disturbed.
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Affiliation(s)
- Hua Wei
- Department of Biochemistry and Molecular Biology, China Medical University, #77 Puhe Road, Shenyang, Liaoning, 110122, China.,Animal Science and Veterinary Medicine College, Shenyang Agricultural University, Shenyang, Liaoning, 110866, China
| | - Guojie Zhao
- Department of Biochemistry and Molecular Biology, China Medical University, #77 Puhe Road, Shenyang, Liaoning, 110122, China
| | - Tianyu Hu
- Department of Biochemistry and Molecular Biology, China Medical University, #77 Puhe Road, Shenyang, Liaoning, 110122, China
| | - Suming Tang
- Department of Biochemistry and Molecular Biology, China Medical University, #77 Puhe Road, Shenyang, Liaoning, 110122, China
| | - Jiquan Jiang
- Department of Biochemistry and Molecular Biology, China Medical University, #77 Puhe Road, Shenyang, Liaoning, 110122, China
| | - Bo Hu
- Department of Biochemistry and Molecular Biology, China Medical University, #77 Puhe Road, Shenyang, Liaoning, 110122, China
| | - Yifu Guan
- Department of Biochemistry and Molecular Biology, China Medical University, #77 Puhe Road, Shenyang, Liaoning, 110122, China
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Ahn JJ, Song HJ, Hong JY, Kim GW, Hwang SY. High specific genotyping method using short target probe and helper probe. Mol Cell Probes 2016; 30:273-276. [PMID: 27223605 DOI: 10.1016/j.mcp.2016.05.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2016] [Revised: 05/09/2016] [Accepted: 05/16/2016] [Indexed: 12/30/2022]
Abstract
Differentiating 1-bp differences using real-time PCR often leads to false-positive results. Therefore, we developed a fluorescence melting curve analysis (FMCA) method with a short target probe and helper probe labeled with a fluorophore and quencher, respectively. This fluorophore and quencher were designed to be near each other when the probes were hybridized to template DNA. The target probe was designed with a shorter length to facilitate a dramatic shift in melting temperature (Tm) upon encountering mismatched hybridization. In FMCA, when the temperature approached the target probe Tm, the target probe would begin to denature from the template DNA, and at the target probe Tm, the fluorescence signal increased markedly. Here, we examined 1-bp differences using the developed method with mitochondrial DNA from Larimichthys polyactis and Larimichthys crocea. Application of this method permitted specific genotype identification for all cases with no cross-reactivity, even when both templates were added to the same tube.
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Affiliation(s)
- Jeong Jin Ahn
- Department of Bio-Nanotechnology, Hanyang University, Sangnok-gu, Ansan, Gyeonggi-do, South Korea
| | - Ha Jeong Song
- Department of Bio-Nanotechnology, Hanyang University, Sangnok-gu, Ansan, Gyeonggi-do, South Korea
| | - Ji Young Hong
- Department of Bio-Nanotechnology, Hanyang University, Sangnok-gu, Ansan, Gyeonggi-do, South Korea
| | - Gi Won Kim
- Department of Molecular and Life Science, Hanyang University, Sangnok-gu, Ansan, Gyeonggi-do, South Korea
| | - Seung Yong Hwang
- Department of Bio-Nanotechnology, Hanyang University, Sangnok-gu, Ansan, Gyeonggi-do, South Korea; Department of Molecular and Life Science, Hanyang University, Sangnok-gu, Ansan, Gyeonggi-do, South Korea.
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Kirimli CE, Shih WH, Shih WY. Amplification-free in situ KRAS point mutation detection at 60 copies per mL in urine in a background of 1000-fold wild type. Analyst 2016; 141:1421-33. [PMID: 26783561 PMCID: PMC4747796 DOI: 10.1039/c5an02048d] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
We have examined the in situ detection of a single-nucleotide KRAS mutation in urine using a (Pb(Mg1/3Nb2/3)O3)0.65(PbTiO3)0.35 (PMN-PT) piezoelectric plate sensor (PEPS) coated with a 17-nucleotide (nt) locked nucleic acid (LNA) probe DNA complementary to the KRAS mutation. To enhance the in situ mutant (MT) DNA detection specificity against the wild type (WT), detection was carried out in a flow with a flow rate of 4 mL min(-1) and at 63 °C with the PEPS vertically situated at the center of the flow in which both the temperature and the flow impingement force discriminated the wild type. Under such conditions, PEPS was shown to specifically detect KRAS MT in situ with 60 copies per mL analytical sensitivity in a background of clinically-relevant 1000-fold more WT in 30 min without DNA isolation, amplification, or labeling. For validation, this detection was followed with detection in a mixture of blue MT fluorescent reporter microspheres (FRMs) (MT FRMs) that bound to only the captured MT and orange WT FRMs that bound to only the captured WT. Microscopic examinations showed that the captured blue MT FRMs still outnumbered the orange WT FRMs by a factor of 4 to 1 even though WT was 1000-fold of MT in urine. Finally, multiplexed specific mutation detection was demonstrated using a 6-PEPS array each with a probe DNA targeting one of the 6 codon-12 KRAS mutations.
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Affiliation(s)
- Ceyhun E Kirimli
- Drexel University, School of Biomedical Engineering, Science, and Health Systems, Philadelphia, Pennsylvania 19104, USA.
| | - Wei-Heng Shih
- Drexel University, Department of Materials Science and Engineering, Philadelphia, Pennsylvania, USA
| | - Wan Y Shih
- Drexel University, School of Biomedical Engineering, Science, and Health Systems, Philadelphia, Pennsylvania 19104, USA.
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Ahn JJ, Kim Y, Hong JY, Kim GW, Kim SY, Hwang SY. Probe-Based Fluorescence Melting Curve Analysis for Differentiating Larimichthys polyactis and Larimichthys crocea. FOOD ANAL METHOD 2016. [DOI: 10.1007/s12161-015-0381-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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Ahn JJ, Kim Y, Hong JY, Kim GW, Kim SY, Hwang SY. Differentiation of Scomber japonicus from Scomber scombrus by using a single locked nucleic acid probe. Mitochondrial DNA A DNA Mapp Seq Anal 2015; 28:379-382. [PMID: 26713370 DOI: 10.3109/19401736.2015.1126831] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Mackerel is marketed at prices according to the species type, Scomber japonicus and Scomber scombrus. Distinguishing these two species with the naked eye is difficult, and their differentiation becomes more difficult after they are processed by cooking, thereby leading to counterfeiting issues. Thus, in this study, we developed a method to differentiate S. japonicus from S. scombrus by detecting polymorphisms in mitochondrial 16 s rRNA gene by using fluorescence melting curve analysis and locked nucleic acid probes. Our method could distinguish S. japonicus from S. scombrus in a single experiment by using a single probe. The probes developed matched exactly with S. japonicus and had a melting temperature of 64 °C. However, the probes were mismatched with S. scombrus, resulting in a lower melting temperature of 46 °C. The high specificity of the locked nucleic acid probes resulted in this large difference in the melting temperatures.
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Affiliation(s)
- Jeong Jin Ahn
- a Department of Bio-Nanotechnology , Hanyang University , Sangnok-Gu , Ansan , Gyeonggi-Do , Korea
| | - Youngjoo Kim
- a Department of Bio-Nanotechnology , Hanyang University , Sangnok-Gu , Ansan , Gyeonggi-Do , Korea
| | - Ji Young Hong
- a Department of Bio-Nanotechnology , Hanyang University , Sangnok-Gu , Ansan , Gyeonggi-Do , Korea
| | - Gi Won Kim
- b Department of Molecular and Life Science , Hanyang University , Sangnok-Gu , Ansan , Gyeonggi-Do , Korea
| | - Seol Young Kim
- a Department of Bio-Nanotechnology , Hanyang University , Sangnok-Gu , Ansan , Gyeonggi-Do , Korea
| | - Seung Yong Hwang
- a Department of Bio-Nanotechnology , Hanyang University , Sangnok-Gu , Ansan , Gyeonggi-Do , Korea.,b Department of Molecular and Life Science , Hanyang University , Sangnok-Gu , Ansan , Gyeonggi-Do , Korea
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Chen R, Gao XB, Yu XL, Song CX, Qiu Y. Novel multiplex PCR assay using locked nucleic acid (LNA)-based universal primers for the simultaneous detection of five swine viruses. J Virol Methods 2015; 228:60-6. [PMID: 26615807 DOI: 10.1016/j.jviromet.2015.11.018] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2015] [Revised: 11/19/2015] [Accepted: 11/20/2015] [Indexed: 02/07/2023]
Abstract
A novel multiplex PCR assay using non-homologous oligonucleotides with locked nucleic acid (LNA) modifications as universal primers was developed and validated for the simultaneous detection of five swine viruses. The assay utilizes five virus-specific primer pairs modified at the 5' end through the addition of the universal primer sequence. In the reaction, small amounts of target templates with the 5' tail were generated and subsequently amplified through the extension of a LNA universal primer set. To validate the specificity of this assay, 27 viral target strains and 12 non-target pathogens were tested. The lower limit of detection of viral nucleic acids was 1.1-1.9 pg per reaction or 11-32 pg in a five-plex viral nucleic acid mixture. The LNA mPCR assay displayed higher analytical sensitivity and efficiency for the detection of plasmid standards compared with the conventional assay, which uses standard primers without the 5' tail. A total of 207 field samples were tested using both assays. The LNA mPCR assay provided numerically higher detection rates for all pathogens in independent samples. Moreover, the LNA mPCR assay had significantly higher detection rates in independent samples compared with the conventional assay.
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Affiliation(s)
- Ru Chen
- Technical Center, Guangdong Entry-Exit Inspection and Quarantine Bureau, Guangzhou 510623, China.
| | - Xiao-Bo Gao
- Department of Genetics, National Research Institute for Family Planning, Beijing 100081, China
| | - Xiao-Lu Yu
- School of Life Sciences, Sun Yat-Sen University, Guangzhou 510675, China
| | - Chang-Xu Song
- Veterinary Medicine Institute, Guangdong Academy of Agricultural Sciences, Guangzhou 510640, China
| | - Yang Qiu
- Technical Center, Guangdong Entry-Exit Inspection and Quarantine Bureau, Guangzhou 510623, China
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Lin CC, Huang WL, Wei F, Su WC, Wong DT. Emerging platforms using liquid biopsy to detect EGFR mutations in lung cancer. Expert Rev Mol Diagn 2015; 15:1427-40. [PMID: 26420338 DOI: 10.1586/14737159.2015.1094379] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Advances in target therapies for lung cancer have enabled detection of gene mutations, specifically those of EGFR. Assays largely depend on the acquisition of tumor tissue biopsy, which is invasive and may not reflect the genomic profile of the tumor at treatment due to tumor heterogeneity or changes that occur during treatment through acquired resistance. Liquid biopsy, a blood test that detects evidence of cancer cells or tumor DNA, has generated considerable interest for its ability to detect EGFR mutations. However, its clinical application is limited by complicated collection methods and the need for technique-dependent platforms. Recently, simpler techniques for EGFR mutant detection in urine or saliva samples have been developed. This review focuses on advances in liquid biopsy and discusses its potential for clinical implementation in lung cancer.
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Affiliation(s)
- Chien-Chung Lin
- a 1 Department of Internal Medicine, Institute of Clinical Medicine, National Cheng Kung University, Hospital, College of Medicine , Tainan, Taiwan
| | - Wei-Lun Huang
- a 1 Department of Internal Medicine, Institute of Clinical Medicine, National Cheng Kung University, Hospital, College of Medicine , Tainan, Taiwan
| | - Fang Wei
- b 2 UCLA - Dentistry, 73-034 CHS UCLA School of Dentistry , 10833 Le Conte Avenue, Los Angeles, California 90095, USA
| | - Wu-Chou Su
- a 1 Department of Internal Medicine, Institute of Clinical Medicine, National Cheng Kung University, Hospital, College of Medicine , Tainan, Taiwan
| | - David T Wong
- b 2 UCLA - Dentistry, 73-034 CHS UCLA School of Dentistry , 10833 Le Conte Avenue, Los Angeles, California 90095, USA
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Ahn JJ, Kim JH, Kim Y, Hong JY, Kim GW, Hwang SY. Multiplex genotyping based on the melting temperature of a single locked nucleic acid probe. Anal Biochem 2015; 491:72-4. [PMID: 26384644 DOI: 10.1016/j.ab.2015.09.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2015] [Revised: 09/08/2015] [Accepted: 09/08/2015] [Indexed: 10/23/2022]
Abstract
Locked nucleic acid (LNA) is a modified RNA nucleotide that can be incorporated at specific positions to generate probes with the desired length, melting temperature (TM), and specificity. Here, we describe a method of multiplex genotyping based on dramatic shifts in the TM of a single dual-labeled LNA probe. Using this method, two varieties of the hairtail fish Trichiurus lepturus can be distinguished from each other, as well as from Trichiurus japonicus, based on a 1- to 2-bp difference in a fragment of mitochondrial cytochrome oxidase subunit 1. The shift in TM was 15 °C for a 1-bp mismatch and 27 °C for a 2-bp mismatch, indicating remarkable specificity. We anticipate that the method will be widely useful in applications such as species identification that require accurate, multiplex, and efficient detection of DNA polymorphisms.
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Affiliation(s)
- Jeong Jin Ahn
- Department of Bio-Nanotechnology, Hanyang University, Ansan, Gyeonggi-do 426-791, Republic of Korea
| | - Ji-Hoon Kim
- Bio-Core Co., Guro-gu, Seoul 152-766, Republic of Korea
| | - Youngjoo Kim
- Department of Bio-Nanotechnology, Hanyang University, Ansan, Gyeonggi-do 426-791, Republic of Korea
| | - Ji Young Hong
- Department of Bio-Nanotechnology, Hanyang University, Ansan, Gyeonggi-do 426-791, Republic of Korea
| | - Gi Won Kim
- Department of Molecular and Life Science, Hanyang University, Ansan, Gyeonggi-do 426-791, Republic of Korea
| | - Seung Yong Hwang
- Department of Bio-Nanotechnology, Hanyang University, Ansan, Gyeonggi-do 426-791, Republic of Korea; Bio-Core Co., Guro-gu, Seoul 152-766, Republic of Korea; Department of Molecular and Life Science, Hanyang University, Ansan, Gyeonggi-do 426-791, Republic of Korea.
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The Emergent Landscape of Detecting EGFR Mutations Using Circulating Tumor DNA in Lung Cancer. BIOMED RESEARCH INTERNATIONAL 2015; 2015:340732. [PMID: 26448936 PMCID: PMC4584057 DOI: 10.1155/2015/340732] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/29/2015] [Accepted: 03/18/2015] [Indexed: 12/18/2022]
Abstract
The advances in targeted therapies for lung cancer are based on the evaluation of specific gene mutations especially the epidermal growth factor receptor (EGFR). The assays largely depend on the acquisition of tumor tissue via biopsy before the initiation of therapy or after the onset of acquired resistance. However, the limitations of tissue biopsy including tumor heterogeneity and insufficient tissues for molecular testing are impotent clinical obstacles for mutation analysis and lung cancer treatment. Due to the invasive procedure of tissue biopsy and the progressive development of drug-resistant EGFR mutations, the effective initial detection and continuous monitoring of EGFR mutations are still unmet requirements. Circulating tumor DNA (ctDNA) detection is a promising biomarker for noninvasive assessment of cancer burden. Recent advancement of sensitive techniques in detecting EGFR mutations using ctDNA enables a broad range of clinical applications, including early detection of disease, prediction of treatment responses, and disease progression. This review not only introduces the biology and clinical implementations of ctDNA but also includes the updating information of recent advancement of techniques for detecting EGFR mutation using ctDNA in lung cancer.
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LNA-modified isothermal oligonucleotide microarray for differentiating bacilli of similar origin. J Biosci 2015; 39:795-804. [PMID: 25431409 DOI: 10.1007/s12038-014-9485-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Oligonucleotide microarray has been one of the most powerful tools in the 'Post-Genome Era' for its high sensitivity, high throughput and parallel processing capability. To achieve high detection specificity, we fabricated an isothermal microarray using locked nucleic acid (LNA)-modified oligonucleotide probes, since LNA has demonstrated the advanced ability to enhance the binding affinity toward their complementary nucleotides. After designing the nucleotide sequences of these oligonucleotide probes for gram-positive bacilli of similar origin (Bacillus subtilis, Bacillus licheniformis, Bacillus pumilus, Bacillus megaterium and Bacillus circulans), we unified the melting temperatures of these oligonucleotide probes by modifying some nucleotides using LNA. Furthermore, we optimized the experimental procedures of hydrating microarray slides, blocking side surface as well as labelling the PCR products. Experimental results revealed that KOD Dash DNA polymerase could efficiently incorporate Cy3-dCTP into the PCR products, and the LNA-isothermal oligonucleotide microarray were able to distinguish the bacilli of similar origin with a high degree of accuracy and specificity under the optimized experimental condition.
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Fakhfakh K, Marais O, Cheng XBJ, Castañeda JR, Hughesman CB, Haynes C. Molecular thermodynamics of LNA:LNA base pairs and the hyperstabilizing effect of 5′-proximal LNA:DNA base pairs. AIChE J 2015. [DOI: 10.1002/aic.14916] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- Kareem Fakhfakh
- Michael Smith Laboratories, University of British Columbia; Vancouver BC Canada
- Dept. of Chemical and Biological Engineering; University of British Columbia; Vancouver BC Canada
| | - Olivia Marais
- Dept. of Chemical and Biological Engineering; University of British Columbia; Vancouver BC Canada
| | - Xin Bo Justin Cheng
- Dept. of Chemical and Biological Engineering; University of British Columbia; Vancouver BC Canada
| | - Jorge Real Castañeda
- Dept. of Chemical and Biological Engineering; University of British Columbia; Vancouver BC Canada
| | - Curtis B. Hughesman
- Michael Smith Laboratories, University of British Columbia; Vancouver BC Canada
| | - Charles Haynes
- Michael Smith Laboratories, University of British Columbia; Vancouver BC Canada
- Dept. of Chemical and Biological Engineering; University of British Columbia; Vancouver BC Canada
- RES'EAU Water Research Network, Dept. of Chemical and Biological Engineering; University of British Columbia; Vancouver BC Canada
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Ahn JJ, Kim Y, Hong JY, Kim GW, Hwang SY. Genotyping of velvet antlers for identification of country of origin using mitochondrial DNA and fluorescence melting curve analysis with locked nucleic acid probes. Mitochondrial DNA A DNA Mapp Seq Anal 2015; 27:2641-4. [PMID: 26094991 DOI: 10.3109/19401736.2015.1041133] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Velvet antlers are used medicinally in Asia and possess various therapeutic effects. Prices are set according to the country of origin, which is unidentifiable to the naked eye, and therefore counterfeiting is prevalent. Additionally, antlers of the Canadian elk, which can generate chronic wasting disease, are prevalently smuggled and distributed in the market. Thus, a method for identifying the country of origin of velvet antlers was developed, using polymorphisms in mitochondrial DNA, fluorescence melting curve analysis and analysis of locked nucleic acids (LNA). This combined method is capable of identifying five genotypes of velvet antlers in a single experiment using two probes. It also has advantages in multiplexing, simplicity and efficiency in genotyping, when compared to real-time PCR or microarrays. The developed method can be used to improve identification rates in the velvet antler market and, by extension, research based on polymorphisms in DNA sequences.
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Affiliation(s)
| | | | | | - Gi Won Kim
- b Department of Molecular and Life Science , Hanyang University , Sangnok-gu, Ansan , Gyeonggi-do , Korea
| | - Seung Yong Hwang
- a Department of Bio-Nanotechnology and.,b Department of Molecular and Life Science , Hanyang University , Sangnok-gu, Ansan , Gyeonggi-do , Korea
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Hughesman C, Fakhfakh K, Bidshahri R, Lund HL, Haynes C. A new general model for predicting melting thermodynamics of complementary and mismatched B-form duplexes containing locked nucleic acids: application to probe design for digital PCR detection of somatic mutations. Biochemistry 2015; 54:1338-52. [PMID: 25654628 DOI: 10.1021/bi500905b] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Advances in real-time polymerase chain reaction (PCR), as well as the emergence of digital PCR (dPCR) and useful modified nucleotide chemistries, including locked nucleic acids (LNAs), have created the potential to improve and expand clinical applications of PCR through their ability to better quantify and differentiate amplification products, but fully realizing this potential will require robust methods for designing dual-labeled hydrolysis probes and predicting their hybridization thermodynamics as a function of their sequence, chemistry, and template complementarity. We present here a nearest-neighbor thermodynamic model that accurately predicts the melting thermodynamics of a short oligonucleotide duplexed either to its perfect complement or to a template containing mismatched base pairs. The model may be applied to pure-DNA duplexes or to duplexes for which one strand contains any number and pattern of LNA substitutions. Perturbations to duplex stability arising from mismatched DNA:DNA or LNA:DNA base pairs are treated at the Gibbs energy level to maintain statistical significance in the regressed model parameters. This approach, when combined with the model's accounting of the temperature dependencies of the melting enthalpy and entropy, permits accurate prediction of T(m) values for pure-DNA homoduplexes or LNA-substituted heteroduplexes containing one or two independent mismatched base pairs. Terms accounting for changes in solution conditions and terminal addition of fluorescent dyes and quenchers are then introduced so that the model may be used to accurately predict and thereby tailor the T(m) of a pure-DNA or LNA-substituted hydrolysis probe when duplexed either to its perfect-match template or to a template harboring a noncomplementary base. The model, which builds on classic nearest-neighbor thermodynamics, should therefore be of use to clinicians and biologists who require probes that distinguish and quantify two closely related alleles in either a quantitative PCR or dPCR assay. This potential is demonstrated by using the model to design allele-specific probes that completely discriminate and quantify clinically relevant mutant alleles (BRAF V600E and KIT D816V) in a dPCR assay.
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Affiliation(s)
- Curtis Hughesman
- Michael Smith Laboratories, University of British Columbia , Vancouver, BC, Canada V6T 1Z4
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Moré G, Schares S, Maksimov A, Conraths FJ, Venturini MC, Schares G. Development of a multiplex real time PCR to differentiate Sarcocystis spp. affecting cattle. Vet Parasitol 2013; 197:85-94. [PMID: 23680541 DOI: 10.1016/j.vetpar.2013.04.024] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2013] [Revised: 03/12/2013] [Accepted: 04/13/2013] [Indexed: 11/16/2022]
Abstract
Cattle are intermediate hosts of Sarcocystis cruzi, Sarcocystis hirsuta and Sarcocystis hominis which use canids, felids or primates as definitive hosts (DH), respectively, and in addition of Sarcocystis sinensis from which the DH is unknown. The aims of the present study were to develop and optimize a multiplex real time PCR for a sensitive and specific differentiation of Sarcocystis spp. affecting cattle and to estimate the prevalence of Sarcocystis spp. in Argentinean cattle. The 18S rRNA genes from individual sarcocysts were amplified and cloned to serve as controls. For the amplification of bovine Sarcocystis spp. a total of 3 primers were used in combination with specific individual probes. Each assay was evaluated and optimized individually and subsequently combined in a multiplex assay (BovSarcoMultiplex real time PCR). The analytical specificity of the multiplex assay was assessed using 5 ng of DNA of heterologous Sarcocystis spp. and other apicomplexan parasites, and no positive reactions were observed other than for the species the PCR targeted. The analytical sensitivity ranged between 0.0125 and 0.125 fg of plasmid DNA (equivalent to the DNA of 2-20 plasmid DNA copies) or resembling DNA of 0.1-0.3 bradyzoites. A total of 380 DNA loin samples from Argentina were tested and 313, 29, 14 and 2 were positive for S. cruzi, S. sinensis, S. hirsuta and S. hominis, respectively. S. sinensis was the most prevalent species among thick walled Sarcocystis spp. in Argentinean cattle. Mixed infections were detected in 8.9% of all samples. Diagnostic sensitivity and specificity for the BovSarcoMultiplex real time PCR relative to previous microscopic examination for thin and thick-walled cyst were 91.5% and 41.7%, 36.3% and 95.9% respectively. Improved DNA extraction methods may allow to further increase the specific and sensitive detection of Sarcocystis spp. in meat samples.
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Affiliation(s)
- Gastón Moré
- Friedrich-Loeffler-Institute, Federal Research Institute for Animal Health, Institute of Epidemiology, Seestrasse 55, 16868 Wusterhausen, Germany.
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Simple and rapid discrimination of embB codon 306 mutations in Mycobacterium tuberculosis clinical isolates by a real-time PCR assay using an LNA-TaqMan probe. J Microbiol Methods 2013; 92:301-6. [DOI: 10.1016/j.mimet.2012.12.014] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2012] [Revised: 12/20/2012] [Accepted: 12/20/2012] [Indexed: 11/19/2022]
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Patel P, Landt O, Kaiser M, Faye O, Koppe T, Lass U, Sall AA, Niedrig M. Development of one-step quantitative reverse transcription PCR for the rapid detection of flaviviruses. Virol J 2013; 10:58. [PMID: 23410000 PMCID: PMC3616844 DOI: 10.1186/1743-422x-10-58] [Citation(s) in RCA: 83] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2011] [Accepted: 02/13/2013] [Indexed: 12/19/2022] Open
Abstract
Background The genus Flavivirus includes several pathogenic agents that cause severe illness in humans. Re-emergence of West Nile virus in Europe and continuous spread of certain flaviviruses such as dengue, yellow fever and Japanese encephalitis viruses represent a global danger to public health. Therefore, a rapid and accurate molecular method is required for diagnostics and epidemiological surveillance of flaviviruses. Methods A Pan-Flavi quantitative RT-PCR assay using a Locked-Nucleic Acid probe targeting the flavivirus NS5 gene was developed and optimized to detect a wide range of flaviviruses simultaneously. The specificity and sensitivity of the Pan-Flavi assay were tested using RNA of different flaviviruses and non-flaviviruses. Furthermore, the assay was compared directly to flavivirus species-specific assays for the ability to detect flaviviruses sensitively. Results Two degenerate primers and one Locked-Nucleic Acids probe were designed to amplify most of the flaviviruses. To increase the specificity and fluorescence signal of the Pan-Flavi assay for detection of yellow fever virus and dengue virus 4, additional primers and probes were included. Viral RNA of thirty different flaviviruses was detected, verifying the broad range specificity. The testing of this assay was successful, using standard plasmid and RNA dilutions of yellow fever virus vaccine strain, dengue virus 1 and tick-borne encephalitis virus, with a sensitivity limit of 10–100 genome copies/reaction. Also comparatively good results were achieved for detecting different flaviviruses by the Pan-Flavi assay when compared to the flavivirus species-specific assays. Conclusion The assay is rapid, broad-range flavivirus-specific and highly sensitive making it a valuable tool for rapid detection of flaviviruses in livestock samples, epidemiological studies or as useful complement to single flavivirus-specific assays for clinical diagnosis.
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Affiliation(s)
- Pranav Patel
- Robert Koch Institute, Center for Biological Security 1 (ZBS1), Nordufer 20, Berlin, 13353, Germany.
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Handy SM, Timme RE, Jacob SM, Deeds JR. Development of a locked nucleic acid real-time polymerase chain reaction assay for the detection of Pinus armandii in mixed species pine nut samples associated with dysgeusia. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2013; 61:1060-1066. [PMID: 23311709 DOI: 10.1021/jf304223a] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Recent work has shown that the presence of the species Pinus armandii , even when occurring as species mixtures of pine nuts, is correlated with taste disturbance (dysgeusia), also referred to as "pine mouth". Because of this known possibility of pine nut mixtures, a need was identified for a rapid streamlined assay to detect the presence of this species in the presence of other types of pine nuts. A locked nucleic acid probe was employed in a real-time polymerase chain reaction (RT-PCR) format to detect a single nucleotide polymorphism (SNP) unique to this species. This assay was able to detect P. armandii in homogenates down to ∼1% concentration (the lowest level tested) in the presence of several commonly co-occurring and closely related species of pine and should prove to be a useful tool for the detection of this species in food products.
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Affiliation(s)
- Sara M Handy
- Center for Food Safety and Applied Nutrition, Office of Regulatory Science, United States Food and Drug Administration-U.S. FDA, College Park, Maryland 20740, USA.
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Mishra S, Ghosh S, Mukhopadhyay R. Maximizing mismatch discrimination by surface-tethered locked nucleic acid probes via ionic tuning. Anal Chem 2013; 85:1615-23. [PMID: 23268627 DOI: 10.1021/ac3028382] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Several investigations on DNA-based nucleic acid sensors performed in the past few years point toward the requirement of an alternative nucleic acid that can detect target DNA strands more efficiently, i.e., with higher sensitivity and selectivity, and can be more robust compared to the DNA sensor probes. Locked nucleic acid (LNA), a conformationally restricted DNA analogue, is potentially a better alternative than DNA, since it is nuclease-resistant, it can form a more stable duplex with DNA in a sequence-specific manner, and it interacts less with substrate surface due to presence of a rigid backbone. In this work, we probed solid-phase dehybridization of ssDNA targets from densely packed fully modified ssLNA probes immobilized onto a gold(111) surface by fluorescence-based measurement of the "on-surface" melting temperatures. We find that mismatch discrimination can be clearly improved by applying the surface-tethered LNA probes, in comparison to the corresponding DNA probes. We show that concentration as well as type of cation (monovalent and polyvalent) can significantly influence thermal stability of the surface-confined LNA-DNA duplexes, the nature of concentration dependence contradicting the solution phase behavior. Since the ionic setting influenced the fully matched duplexes more strongly than the singly mismatched duplexes, the mismatch discrimination ability of the surface-confined LNA probes could be controlled by ionic modulations. To our knowledge, this is the first report on ionic regulation of melting behavior of surface-confined LNA-DNA duplexes.
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Affiliation(s)
- Sourav Mishra
- Department of Biological Chemistry, Indian Association for the Cultivation of Science, Jadavpur, Kolkata-700032, India
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Lundin KE, Højland T, Hansen BR, Persson R, Bramsen JB, Kjems J, Koch T, Wengel J, Smith CIE. Biological activity and biotechnological aspects of locked nucleic acids. ADVANCES IN GENETICS 2013; 82:47-107. [PMID: 23721720 DOI: 10.1016/b978-0-12-407676-1.00002-0] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Locked nucleic acid (LNA) is one of the most promising new nucleic acid analogues that has been produced under the past two decades. In this chapter, we have tried to cover many of the different areas, where this molecule has been used to improve the function of synthetic oligonucleotides (ONs). The use of LNA in antisense ONs, including gapmers, splice-switching ONs, and siLNA, as well as antigene ONs, is reviewed. Pharmacokinetics as well as pharmacodynamics of LNA ONs and a description of selected compounds in, or close to, clinical testing are described. In addition, new LNA modifications and the adaptation of enzymes for LNA incorporation are reviewed. Such enzymes may become important for the development of stabilized LNA-containing aptamers.
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Affiliation(s)
- Karin E Lundin
- Clinical Research Center, Department of Laboratory Medicine, Karolinska Institutet, Novum, Huddinge, Stockholm, Sweden.
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Yan Y, Yan J, Piao X, Zhang T, Guan Y. Effect of LNA- and OMeN-modified oligonucleotide probes on the stability and discrimination of mismatched base pairs of duplexes. J Biosci 2012; 37:233-41. [PMID: 22581329 DOI: 10.1007/s12038-012-9196-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
Locked nucleic acid (LNA) and 2'-O-methyl nucleotide (OMeN) are the most extensively studied nucleotide analogues. Although both LNA and OMeN are characterized by the C3'-endo sugar pucker conformation, which is dominant in A-form DNA and RNA nucleotides, they demonstrate different binding behaviours. Previous studies have focused attention on their properties of duplex stabilities, hybridization kinetics and resistance against nuclease digestion; however, their ability to discriminate mismatched hybridizations has been explored much less. In this study, LNA- and OMeN-modified oligonucleotide probes have been prepared and their effects on the DNA duplex stability have been examined: LNA modifications can enhance the duplex stability, whereas OMeN modifications reduce the duplex stability. Next, we studied how the LNA:DNA and OMeN:DNA mismatches reduced the duplex stability. Melting temperature measurement showed that different LNA:DNA or OMeN:DNA mismatches indeed influence the duplex stability differently. LNA purines can discriminate LNA:DNA mismatches more effectively than LNA pyrimidines as well as DNA nucleotides. Furthermore, we designed five LNA- and five OMeN-modified oligonucleotide probes to simulate realistic situations where target-probe duplexes contain a complementary LNA:DNA or OMeN:DNA base pairs and a DNA:DNA mismatch simultaneously. The measured collective effect showed that the duplex stability was enhanced by the complementary LNA:DNA base pair but decreased by the DNA:DNA mismatch in a position-dependent manner regardless of the chemical identity and position of the complementary LNA:DNA base pair. On the other hand, the OMeN-modified probes also showed that the duplex stability was reduced by both the OMeN modification and the OMeN:DNA mismatch in a position-dependent manner.
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Affiliation(s)
- Ying Yan
- Department of Biochemistry and Molecular Biology, Key Laboratory of Medical Cell Biology of Minister of Education, China Medical University, Shenyang, Liaoning, 110001, China
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Zhelev DV, Hunt M, Le A, Dupuis C, Ren S, Gibbons HS. Effect of the Bacillus atrophaeus subsp. globigii Spo0F H101R mutation on strain fitness. Appl Environ Microbiol 2012; 78:8601-10. [PMID: 23042165 PMCID: PMC3502920 DOI: 10.1128/aem.01922-12] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2012] [Accepted: 09/24/2012] [Indexed: 11/20/2022] Open
Abstract
Sporulation is a critical developmental process in Bacillus spp. that, once initiated, removes the possibility of further growth until germination. Therefore, the threshold conditions triggering sporulation are likely to be subject to evolutionary constraint. Our previous studies revealed two spontaneous hypersporulating mutants of Bacillus atrophaeus subsp. globigii, both containing point mutations in the spo0F gene. One of these strains (Detrick-2; contains the spo0F101 allele with a C:T [His101Arg] substitution) had been deliberately selected in the early 1940s as an anthrax surrogate. To determine whether the experimental conditions used during the selection of the "military" strains could have supported the emergence of hypersporulating variants, the relative fitness of strain Detrick-2 was measured in several experimental settings modeled on experimental conditions employed during its development in the 1940s as a simulant. The congenic strain Detrick-1 contained a wild-type spo0F gene and sporulated like the wild-type strain. The relative fitness of Detrick-1 and Detrick-2 was evaluated in competition experiments using quantitative single nucleotide polymorphism (SNP)-specific real-time PCR assays directed at the C:T substitution. The ancestral strain Detrick-1 had a fitness advantage under all conditions tested except when competing cultures were subjected to frequent heat shocks. The hypersporulating strain gained the maximum fitness advantage when cultures were grown at low oxygen tension and when heat shock was applied soon after the formation of the first heat-resistant spores. This is interpreted as gain of fitness by the hypersporulating strain in fast-changing fluctuating environments as a result of the increased rate of switching to the sporulating phenotype.
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Affiliation(s)
- Doncho V. Zhelev
- Sensors and Electron Devices Directorate, Army Research Laboratory, Adelphi, Maryland, USA
| | - Mia Hunt
- Sensors and Electron Devices Directorate, Army Research Laboratory, Adelphi, Maryland, USA
| | - Anna Le
- Sensors and Electron Devices Directorate, Army Research Laboratory, Adelphi, Maryland, USA
| | - Christopher Dupuis
- Sensors and Electron Devices Directorate, Army Research Laboratory, Adelphi, Maryland, USA
| | - Suelynn Ren
- Sensors and Electron Devices Directorate, Army Research Laboratory, Adelphi, Maryland, USA
| | - Henry S. Gibbons
- Edgewood Chemical Biological Center, Aberdeen Proving Ground, Maryland, USA
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Liu Y, Döring J, Hurek T. Bias in topoisomerase (TOPO)-cloning of multitemplate PCR products using locked nucleic acid (LNA)-substituted primers. J Microbiol Methods 2012; 91:483-6. [PMID: 23064262 DOI: 10.1016/j.mimet.2012.10.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2012] [Revised: 10/05/2012] [Accepted: 10/06/2012] [Indexed: 11/15/2022]
Abstract
Locked nucleic acid (LNA) modifications help to improve nucleic acid recognition in molecular biology applications. We report that LNA-substituted primers in PCR reactions may cause considerable cloning bias when the widely used topoisomerase-based ligation is used for cloning of multitemplate PCR products.
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Affiliation(s)
- Yuan Liu
- University of Bremen, Department of Microbe-Plant Interactions, CBIB (Center for Biomolecular Interactions Bremen), 28359 Bremen, Germany
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