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Zhao G, Xue Y, Dai Y, Zhou X, Li H, Sheng G, Xu H, Chen Y. One-step reverse transcriptase-free miRNA detection system and its application for detection of gastrointestinal cancers. Talanta 2024; 278:126457. [PMID: 38917550 DOI: 10.1016/j.talanta.2024.126457] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2024] [Revised: 05/09/2024] [Accepted: 06/19/2024] [Indexed: 06/27/2024]
Abstract
MicroRNAs (miRNAs) play pivotal roles in gene regulation and their dysregulation is implicated in various diseases, including cancer. Current methods for miRNA analysis often involve complex procedures and high costs, limiting their clinical utility. Therefore, there is a critical need for the development of simpler and more cost-effective miRNA detection techniques to enable early disease diagnosis. In this study, we introduce a novel one-enzyme for miRNA one-step detection method using Taq DNA polymerase, termed OSMOS-qPCR. We optimized the PCR buffer, PCR program, Taq DNA Polymerase concentrations and reverse PCR primer concentrations, resulted in a wide linear range from 100 fM to 0.001 fM (R2 > 0.98 for each miRNA), the detection limit for OSMOS-qPCR was 0.0025 fM. Furthermore, OSMOS-qPCR demonstrates excellent specificity to differentiation of less than 0.1 % nonspecific signal. Finally, we demonstrated the robust amplification efficiency, enabling the detection of trace amounts of cell-free miRNA in serum samples, and the excellent discrimination ability between gastrointestinal cancers and control subjects (AUC value = 1.0) if combined two miRNAs. The development of OSMOS-qPCR offering a simpler, cost-effective, and efficient detection method, has the potential to be non-invasive strategy for early detection of gastrointestinal cancers.
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Affiliation(s)
- Guodong Zhao
- Zhejiang University of Technology, Zhejiang, Hangzhou 310014, China; ZJUT Yinhu Research Institute of Innovation and Entrepreneurship, Zhejiang, Hangzhou 311400, China; Department of Spleen and Stomach Diseases, Kunshan Hospital of Traditional Chinese Medicine, Kunshan Jiangsu 215300, China; State Key Laboratory of Digital Medical Engineering, School of Biological Science and Medical Engineering, Southeast University, Nanjing 211189, China.
| | - Ying Xue
- The Affiliated Suzhou Hospital of Nanjing Medical University, Suzhou Municipal Hospital, Gusu School, Nanjing Medical University, Suzhou Jiangsu 215000, China.
| | - Yanmiao Dai
- Department of Spleen and Stomach Diseases, Kunshan Hospital of Traditional Chinese Medicine, Kunshan Jiangsu 215300, China
| | - Xiaojin Zhou
- State Key Laboratory of Digital Medical Engineering, School of Biological Science and Medical Engineering, Southeast University, Nanjing 211189, China
| | - Hui Li
- Department of Gastroenterology, The First People's Hospital of Xuzhou, The Affiliated Xuzhou Municipal Hospital of Xuzhou Medical University, Xuzhou Jiangsu 221002, China
| | - Guangsen Sheng
- Clinical Laboratory, Xuzhou New Health Hospital, Xuzhou 221005, China
| | - Hongwei Xu
- Department of Spleen and Stomach Diseases, Kunshan Hospital of Traditional Chinese Medicine, Kunshan Jiangsu 215300, China.
| | - Ying Chen
- School of Medical Technology, Xuzhou Medical University, Xuzhou 221004, China.
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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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Kim KW, Lee B, Eom S, Shin D, Park C, Kim S, Yi H. Universal primers for rift valley fever virus whole-genome sequencing. Sci Rep 2023; 13:18688. [PMID: 37907670 PMCID: PMC10618441 DOI: 10.1038/s41598-023-45848-z] [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] [Received: 02/08/2023] [Accepted: 10/24/2023] [Indexed: 11/02/2023] Open
Abstract
Rift Valley fever (RVF) is a mosquito-borne zoonotic disease causing acute hemorrhagic fever. Accurate identification of mutations and phylogenetic characterization of RVF virus (RVFV) require whole-genome analysis. Universal primers to amplify the entire RVFV genome from clinical samples with low copy numbers are currently unavailable. Thus, we aimed to develop universal primers applicable for all known RVFV strains. Based on the genome sequences available from public databases, we designed eight pairs of universal PCR primers covering the entire RVFV genome. To evaluate primer universality, four RVFV strains (ZH548, Kenya 56 (IB8), BIME-01, and Lunyo), encompassing viral phylogenetic diversity, were chosen. The nucleic acids of the test strains were chemically synthesized or extracted via cell culture. These RNAs were evaluated using the PCR primers, resulting in successful amplification with expected sizes (0.8-1.7 kb). Sequencing confirmed that the products covered the entire genome of the RVFV strains tested. Primer specificity was confirmed via in silico comparison against all non-redundant nucleotide sequences using the BLASTn alignment tool in the NCBI database. To assess the clinical applicability of the primers, mock clinical specimens containing human and RVFV RNAs were prepared. The entire RVFV genome was successfully amplified and sequenced at a viral concentration of 108 copies/mL. Given the universality, specificity, and clinical applicability of the primers, we anticipate that the RVFV universal primer pairs and the developed method will aid in RVFV phylogenomics and mutation detection.
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Affiliation(s)
- Kwan Woo Kim
- Department of Public Health Sciences, Graduate School, Korea University, Seoul, Republic of Korea
- Interdisciplinary Program in Precision Public Health, Korea University, Seoul, Republic of Korea
- Center for Study of Emerging and Re-emerging Viruses, Korea Virus Research Institute, Institute for Basic Science (IBS), Daejeon, Republic of Korea
| | - Banseok Lee
- Interdisciplinary Program in Precision Public Health, Korea University, Seoul, Republic of Korea
- Integrated Biomedical and Life Science, Graduate School, Korea University, Seoul, Republic of Korea
| | - Sujeong Eom
- Interdisciplinary Program in Precision Public Health, Korea University, Seoul, Republic of Korea
- Integrated Biomedical and Life Science, Graduate School, Korea University, Seoul, Republic of Korea
| | - Donghoon Shin
- Interdisciplinary Program in Precision Public Health, Korea University, Seoul, Republic of Korea
- Integrated Biomedical and Life Science, Graduate School, Korea University, Seoul, Republic of Korea
| | - Changwoo Park
- Microbiological Analysis Team, Group for Biometrology, Korea Research Institute of Standards and Science (KRISS), Daejeon, Republic of Korea
- Convergent Research Center for Emerging Virus Infection, Korea Research Institute of Chemical Technology (KRICT), Daejeon, Republic of Korea
- Department of Agricultural Biotechnology, Seoul National University, Seoul, Republic of Korea
| | - Seil Kim
- Microbiological Analysis Team, Group for Biometrology, Korea Research Institute of Standards and Science (KRISS), Daejeon, Republic of Korea.
- Convergent Research Center for Emerging Virus Infection, Korea Research Institute of Chemical Technology (KRICT), Daejeon, Republic of Korea.
- Department of Bio-Analysis Science, University of Science and Technology, Daejeon, Republic of Korea.
| | - Hana Yi
- Interdisciplinary Program in Precision Public Health, Korea University, Seoul, Republic of Korea.
- Integrated Biomedical and Life Science, Graduate School, Korea University, Seoul, Republic of Korea.
- School of Biosystems and Biomedical Sciences, Korea University, Seoul, Republic of Korea.
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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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Ma Y, Zheng M. Improved PCR by the Use of Disruptors, a New Class of Oligonucleotide Reagents. Methods Mol Biol 2023; 2967:159-171. [PMID: 37608110 DOI: 10.1007/978-1-0716-3358-8_13] [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] [Indexed: 08/24/2023]
Abstract
As a powerful tool, polymerase chain reaction (PCR) has been indispensable and widely used in a large array of applications. In practice, many factors may affect the overall performance of a PCR. One such factor is the stability of intramolecular secondary structure formed within single-stranded template. The higher the stability of such a structure, the more likely it will have adverse effects on PCR performance. Traditionally, chemical reagents believed to reduce the stability of nucleic acid secondary structures, such as DMSO and betaine, have been used to mitigate their adverse effects on PCR performance. However, these reagents have apparent downsides including increasing replication error rate, inhibiting polymerase activity, and being ineffective against secondary structures of very high stabilities. Disruptors, a new class of oligonucleotide reagents, do not exhibit such downsides. They are specifically designed to target intramolecular secondary structures only without any effect on the replication of other regions of the template. Their effective concentration range for improving PCR performance is well tolerated by PCR. And they are very effective in improving PCR performance on templates that are notoriously difficult to amplify by PCR even in the presence of DMSO or betaine, e.g., the inverted terminal repeat of adeno-associated virus (AAV-ITR). In this chapter, the application of disruptors in PCR is described with AAV-ITR as the example template.
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Affiliation(s)
- Yong Ma
- School of Biomedical Engineering (Suzhou), Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui, China
- Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences, Suzhou, Jiangsu, China
| | - Minxue Zheng
- School of Biomedical Engineering (Suzhou), Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui, China.
- Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences, Suzhou, Jiangsu, China.
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Moon YJ, Lee SY, Oh SW. A Review of Isothermal Amplification Methods and Food-Origin Inhibitors against Detecting Food-Borne Pathogens. Foods 2022; 11:foods11030322. [PMID: 35159473 PMCID: PMC8833899 DOI: 10.3390/foods11030322] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Revised: 01/17/2022] [Accepted: 01/18/2022] [Indexed: 02/06/2023] Open
Abstract
The isothermal amplification method, a molecular-based diagnostic technology, such as loop-mediated isothermal amplification (LAMP) and recombinase polymerase amplification (RPA), is widely used as an alternative to the time-consuming and labor-intensive culture-based detection method. However, food matrices or other compounds can inhibit molecular-based diagnostic technologies, causing reduced detection efficiencies, and false-negative results. These inhibitors originating from food are polysaccharides and polyphenolic compounds in berries, seafood, and vegetables. Additionally, magnesium ions needed for amplification reactions can also inhibit molecular-based diagnostics. The successful removal of inhibitors originating from food and molecular amplification reaction is therefore proposed to enhance the efficiency of molecular-based diagnostics and allow accurate detection of food-borne pathogens. Among molecular-based diagnostics, PCR inhibitors have been reported. Nevertheless, reports on the mechanism and removal of isothermal amplification method inhibitors are insufficient. Therefore, this review describes inhibitors originating from food and some compounds inhibiting the detection of food-borne pathogens during isothermal amplification.
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Disruptors, a new class of oligonucleotide reagents, significantly improved PCR performance on templates containing stable intramolecular secondary structures. Anal Biochem 2021; 624:114169. [PMID: 33766577 DOI: 10.1016/j.ab.2021.114169] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Revised: 03/09/2021] [Accepted: 03/10/2021] [Indexed: 11/21/2022]
Abstract
Intramolecular secondary structures within templates have been shown to lower PCR performance. Whereas many approaches have been developed to mitigate such impairment on PCR, their effects can vary greatly depending on template sequences. Here we present a novel, universally effective approach to improve PCR performance involving specifically designed oligonucleotides called disruptors. A disruptor contained three functional components, an anchor designed to initiate template binding, an effector to disrupt intramolecular secondary structure, and a 3' blocker to prevent its elongation by DNA polymerase. A functional mechanism for a disruptor to improve PCR efficiency was proposed where anchor first binds to template followed by effector-mediated strand displacement to unwind intramolecular secondary structure. Such a mechanism was consistent with the observation that anchor played a more critical role for disruptor function. As an example of potential disruptor applications, inverted terminal repeat sequences of recombinant adeno-associated virus vectors were successfully amplified in the presence of disruptors despite their well-known reputation as some of the most difficult templates for PCR amplification and Sanger sequencing due to their ultra-stable T-shaped hairpin structures. In stark contrast, both DMSO and betaine, two PCR additives routinely used to facilitate PCR amplification and Sanger sequencing of GC-rich templates, did not demonstrate any improving effect.
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