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Demidenko NV, Logacheva MD, Penin AA. Selection and validation of reference genes for quantitative real-time PCR in buckwheat (Fagopyrum esculentum) based on transcriptome sequence data. PLoS One 2011; 6:e19434. [PMID: 21589908 PMCID: PMC3093374 DOI: 10.1371/journal.pone.0019434] [Citation(s) in RCA: 95] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2011] [Accepted: 03/29/2011] [Indexed: 11/18/2022] Open
Abstract
Quantitative reverse transcription PCR (qRT-PCR) is one of the most precise and widely used methods of gene expression analysis. A necessary prerequisite of exact and reliable data is the accurate choice of reference genes. We studied the expression stability of potential reference genes in common buckwheat (Fagopyrum esculentum) in order to find the optimal reference for gene expression analysis in this economically important crop. Recently sequenced buckwheat floral transcriptome was used as source of sequence information. Expression stability of eight candidate reference genes was assessed in different plant structures (leaves and inflorescences at two stages of development and fruits). These genes are the orthologs of Arabidopsis genes identified as stable in a genome-wide survey gene of expression stability and a traditionally used housekeeping gene GAPDH. Three software applications – geNorm, NormFinder and BestKeeper - were used to estimate expression stability and provided congruent results. The orthologs of AT4G33380 (expressed protein of unknown function, Expressed1), AT2G28390 (SAND family protein, SAND) and AT5G46630 (clathrin adapter complex subunit family protein, CACS) are revealed as the most stable. We recommend using the combination of Expressed1, SAND and CACS for the normalization of gene expression data in studies on buckwheat using qRT-PCR. These genes are listed among five the most stably expressed in Arabidopsis that emphasizes utility of the studies on model plants as a framework for other species.
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Affiliation(s)
- Natalia V. Demidenko
- Department of Genetics, Biological Faculty, M.V. Lomonosov Moscow State University, Moscow, Russia
| | - Maria D. Logacheva
- Department of Evolutionary Biochemistry, A.N. Belozersky Institute of Physico-Chemical Biology, M.V. Lomonosov Moscow State University, Moscow, Russia
- Evolutionary Genomics Laboratory, Faculty of Bioengineering and Bioinformatics, M.V. Lomonosov Moscow State University, Moscow, Russia
- A.A. Kharkevich Institute for Information Transmission Problems, Russian Academy of Science, Moscow, Russia
| | - Aleksey A. Penin
- Department of Genetics, Biological Faculty, M.V. Lomonosov Moscow State University, Moscow, Russia
- Evolutionary Genomics Laboratory, Faculty of Bioengineering and Bioinformatics, M.V. Lomonosov Moscow State University, Moscow, Russia
- A.A. Kharkevich Institute for Information Transmission Problems, Russian Academy of Science, Moscow, Russia
- * E-mail:
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152
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Horáková H, Polakovičová I, Shaik GM, Eitler J, Bugajev V, Dráberová L, Dráber P. 1,2-propanediol-trehalose mixture as a potent quantitative real-time PCR enhancer. BMC Biotechnol 2011; 11:41. [PMID: 21501492 PMCID: PMC3102612 DOI: 10.1186/1472-6750-11-41] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2010] [Accepted: 04/18/2011] [Indexed: 12/04/2022] Open
Abstract
Background Quantitative real-time PCR (qPCR) is becoming increasingly important for DNA genotyping and gene expression analysis. For continuous monitoring of the production of PCR amplicons DNA-intercalating dyes are widely used. Recently, we have introduced a new qPCR mix which showed improved amplification of medium-size genomic DNA fragments in the presence of DNA dye SYBR green I (SGI). In this study we tested whether the new PCR mix is also suitable for other DNA dyes used for qPCR and whether it can be applied for amplification of DNA fragments which are difficult to amplify. Results We found that several DNA dyes (SGI, SYTO-9, SYTO-13, SYTO-82, EvaGreen, LCGreen or ResoLight) exhibited optimum qPCR performance in buffers of different salt composition. Fidelity assays demonstrated that the observed differences were not caused by changes in Taq DNA polymerase induced mutation frequencies in PCR mixes of different salt composition or containing different DNA dyes. In search for a PCR mix compatible with all the DNA dyes, and suitable for efficient amplification of difficult-to-amplify DNA templates, such as those in whole blood, of medium size and/or GC-rich, we found excellent performance of a PCR mix supplemented with 1 M 1,2-propanediol and 0.2 M trehalose (PT enhancer). These two additives together decreased DNA melting temperature and efficiently neutralized PCR inhibitors present in blood samples. They also made possible more efficient amplification of GC-rich templates than betaine and other previously described additives. Furthermore, amplification in the presence of PT enhancer increased the robustness and performance of routinely used qPCRs with short amplicons. Conclusions The combined data indicate that PCR mixes supplemented with PT enhancer are suitable for DNA amplification in the presence of various DNA dyes and for a variety of templates which otherwise can be amplified with difficulty.
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Affiliation(s)
- Helena Horáková
- Department of Signal Transduction, Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, Vídeňská 1083, 142 20 Prague 4, Czech Republic
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153
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Temesvári M, Paulik J, Kóbori L, Monostory K. High-resolution melting curve analysis to establish CYP2C19∗2 single nucleotide polymorphism: Comparison with hydrolysis SNP analysis. Mol Cell Probes 2011; 25:130-3. [DOI: 10.1016/j.mcp.2011.01.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2010] [Revised: 01/07/2011] [Accepted: 01/10/2011] [Indexed: 11/27/2022]
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154
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Guthrie PAI, Gaunt TR, Abdollahi MR, Rodriguez S, Lawlor DA, Smith GD, Day INM. Amplification ratio control system for copy number variation genotyping. Nucleic Acids Res 2011; 39:e54. [PMID: 21300641 PMCID: PMC3082892 DOI: 10.1093/nar/gkr046] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
We describe a generic design for ratiometric analysis suitable for determination of copy number variation (CNV) class of a gene. Following two initial sequence-specific PCR priming cycles, both ends of both amplicons (one test and one reference) in a duplex reaction, are all primed by the same universal primer (UP). Following each amplification denaturation step, the UP target and its reverse complement (UP′) in each strand form a hairpin. The bases immediately beyond the 3′-end of the UP and 5′ of UP′ are chosen such as not to base pair in the hairpin (otherwise priming is ablated). This hairpin creates a single constant environment for priming events and chaperones free 3′-ends of amplicon strands. The resultant ‘amplification ratio control system’ (ARCS) permits ratiometric representation of amplicons relative to the original template into PCR plateau phase. These advantages circumvent the need for real-time PCR for quantitation. Choice of different %(G+C) content for the target and reference amplicons allows liquid phase thermal melt discrimination and quantitation of amplicons. The design is generic, simple to set up and economical. Comparisons with real-time PCR and other techniques are made and CNV assays demonstrated for haptoglobin duplicon and ‘chemokine (C-C motif) ligand 3-like 1’ gene.
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Affiliation(s)
- Philip A I Guthrie
- Bristol Genetic Epidemiology Laboratory and MRC Centre for Causal Analyses in Translational Epidemiology, School of Social and Community Medicine, University of Bristol, Oakfield Grove, Clifton BS8 2BN, UK.
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155
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Khan SA, Sung K, Nawaz MS. Detection of aacA-aphD, qacEδ1, marA, floR, and tetA genes from multidrug-resistant bacteria: Comparative analysis of real-time multiplex PCR assays using EvaGreen(®) and SYBR(®) Green I dyes. Mol Cell Probes 2011; 25:78-86. [PMID: 21256956 DOI: 10.1016/j.mcp.2011.01.004] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2010] [Revised: 01/07/2011] [Accepted: 01/13/2011] [Indexed: 11/18/2022]
Abstract
We have developed multiplex real-time PCR assays that utilize DNA-intercalating dyes, SYBR Green I (SG) and EvaGreen (EG), with two primer sets (set 1=qacEδ1, tetA and aacA-aphD; set 2=tetA, marA, and floR) to simultaneously amplify the qacEδ1, tetA, aacA-aphD, marA, and floR genes. Validity of the multiplex PCR assays was confirmed by testing 83 bacterial isolates, including Staphylococcus aureus (28 isolates), Enterococcus spp. (17 isolates), Salmonella enterica serovar Typhimurium (8 isolates), Citrobacter spp. (9 isolates), Escherichia coli (14 isolates) and Aeromonas veronii (7 isolates), and performing sequence analysis of representative PCR products. Agarose gel analysis revealed the presence of correct size PCR products, and the differences in their thermal melting (T(m)) curves were used to distinguish various PCR products. Although T(m) peaks of different amplicons after EG-based singleplex and multiplex PCR assays were resolved nicely, only one or two peaks were seen for SG-bound amplicons. EG-based multiplex real-time PCR assays provided better peak resolution. There was a good correlation with a better linear relationship between the C(t) and log input DNA concentration for the set 1 and set 2 genes in EG-based assays (R(EG)(2)=0.9813and0.9803) than in SG-based assays (R(SG)(2)=0.5276and0.6255). The sensitivities of detection were 2.5-25fg and 25-250fg of template DNA in EG and SG-based singleplex and multiplex PCR assays, respectively. The assays, which could be completed in less than 45min, offer sensitive and rapid detection of qacEδ1, aacA-aphD, marA, floR, and tetA genes from a diverse group of multiple antibiotic-resistant bacterial strains.
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Affiliation(s)
- Saeed A Khan
- Division of Microbiology, National Center for Toxicological Research, Jefferson, AR 72079, United States.
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156
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Cressina E, Chen L, Abell C, Leeper FJ, Smith AG. Fragment screening against the thiamine pyrophosphate riboswitchthiM. Chem Sci 2011. [DOI: 10.1039/c0sc00406e] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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157
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Zhang Y, OuYang S, Zhang L, Tang X, Song Z, Liu P. Oxygen-induced changes in mitochondrial DNA and DNA repair enzymes in aging rat lens. Mech Ageing Dev 2010; 131:666-73. [DOI: 10.1016/j.mad.2010.09.003] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2010] [Revised: 08/26/2010] [Accepted: 09/11/2010] [Indexed: 02/03/2023]
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158
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Schaerli Y, Stein V, Spiering MM, Benkovic SJ, Abell C, Hollfelder F. Isothermal DNA amplification using the T4 replisome: circular nicking endonuclease-dependent amplification and primase-based whole-genome amplification. Nucleic Acids Res 2010; 38:e201. [PMID: 20921065 PMCID: PMC3001092 DOI: 10.1093/nar/gkq795] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
In vitro reconstitution of the bacteriophage T4 replication machinery provides a novel system for fast and processive isothermal DNA amplification. We have characterized this system in two formats: (i) in circular nicking endonuclease-dependent amplification (cNDA), the T4 replisome is supplemented with a nicking endonuclease (Nb.BbvCI) and a reverse primer to generate a well-defined uniform double-stranded linear product and to achieve up to 1100-fold linear amplification of a plasmid in 1 h. (ii) The T4 replisome with its primase (gp61) can also support priming and exponential amplification of genomic DNA in primase-based whole-genome amplification (T4 pWGA). Low amplification biases between 4.8 and 9.8 among eight loci for 0.3–10 ng template DNA suggest that this method is indeed suitable for uniform whole-genome amplification. Finally, the utility of the T4 replisome for isothermal DNA amplification is demonstrated in various applications, including incorporation of functional tags for DNA labeling and immobilization; template generation for in vitro transcription/translation and sequencing; and colony screening and DNA quantification.
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Affiliation(s)
- Yolanda Schaerli
- Department of Biochemistry, University of Cambridge, Cambridge, UK
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159
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Smyth RP, Schlub TE, Grimm A, Venturi V, Chopra A, Mallal S, Davenport MP, Mak J. Reducing chimera formation during PCR amplification to ensure accurate genotyping. Gene 2010; 469:45-51. [PMID: 20833233 DOI: 10.1016/j.gene.2010.08.009] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2010] [Revised: 08/27/2010] [Accepted: 08/30/2010] [Indexed: 11/28/2022]
Abstract
Measurements of population diversity are fundamental to the reconstruction of the evolutionary and epidemiological history of organisms. Commonly used protocols to measure population diversity using the polymerase chain reaction (PCR) are prone to the introduction of artificial chimeras. These are often difficult to detect and can confound the correct interpretation of results due to the false generation of recombinants when the underlying DNA sample contains multiple distinct templates. This study presents a standardised procedure to suppress the formation of artificial chimeras during PCR amplification. The solution is based on the accurate determination of the efficiency and end point of the log-linear phase of a PCR. This procedure will facilitate the generation of data sets that more accurately reflect the underlying population diversity rather than artifacts introduced by the process itself.
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Affiliation(s)
- R P Smyth
- Centre for Virology, Burnet Institute, 85 Commercial Road, Melbourne, Victoria, Australia
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160
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Zhang Y, Zhang L, Zhang L, Bai J, Ge H, Liu P. Expression changes in DNA repair enzymes and mitochondrial DNA damage in aging rat lens. Mol Vis 2010; 16:1754-63. [PMID: 20808729 PMCID: PMC2929939] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2010] [Accepted: 08/24/2010] [Indexed: 12/04/2022] Open
Abstract
PURPOSE To determine if there is increased mitochondrial DNA (mtDNA) and nuclear DNA (nDNA) damage with age in the lenses of rats. We also explored the immunolocalization of 8-oxoguanine DNA glycosylase 1 (OGG1) and AP endonuclease 1 (APE1) in the lens and studied three of the predominant base excision repair (BER) enzymes: OGG1, APE1, and DNA polymerase gamma (Polgamma). METHODS The methods used by this study include the selection of twenty-six male Wistar rats in each group (2 months old and 26 months old) and fourteen male Wistar rats in the 16 months old group. The total DNA of lenses were isolated and the DNA genome was amplified by a long extension-polymerase chain reaction (LX-PCR). We examined mtDNA and nDNA damage with a quantitative polymerase chain reaction (QPCR) assay that was combined with EvaGreen. We also studied the gene expression of mRNA and protein in these key BER enzymes with real time-polymerase chain reaction (RT-PCR) and western blot analysis. RESULTS There was an increase in oxidative DNA damage, which exists primarily in the mtDNA. The amount of 8-hydroxy-2'-deoxy-guanosine (8-OHdG) in DNA was significantly increased with age. Our experiments demonstrated that the gene expression of mRNA and protein in these key BER enzymes decreased with age. OGG1 and APE1 were localized by immunohistochemistry within lens epithelial cells (LECs) and superficial fiber cells. CONCLUSIONS The gene expression of mRNA and protein in these key BER enzymes decreased with age, which caused a decrease in the repairing capability of the mtDNA and the accumulation of mtDNA damage. The increased mtDNA damage and decreased expression of BER enzymes may cause a "vicious cycle" of oxidative stress that contributes to the accumulation of mtDNA mutations and age-related cataract pathogenesis.
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Affiliation(s)
- Yi Zhang
- Eye hospital, The First Affiliated Hospital, Harbin Medical University, Harbin, China
| | - Lu Zhang
- Eye hospital, The First Affiliated Hospital, Harbin Medical University, Harbin, China
| | - Lan Zhang
- Cardiovascular medicine, The Fourth Affiliated Hospital, Harbin Medical University, Harbin, China
| | - Jie Bai
- Eye hospital, The First Affiliated Hospital, Harbin Medical University, Harbin, China
| | - HongYan Ge
- Eye hospital, The First Affiliated Hospital, Harbin Medical University, Harbin, China
| | - Ping Liu
- Eye hospital, The First Affiliated Hospital, Harbin Medical University, Harbin, China
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161
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Ruedas-Rama MJ, Alvarez-Pez JM, Paredes JM, Talavera EM, Orte A. Binding of BOBO-3 intercalative dye to DNA homo-oligonucleotides with different base compositions. J Phys Chem B 2010; 114:6713-21. [PMID: 20415455 DOI: 10.1021/jp1010742] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The interactions between trimethine cyanine homodimer dye, BOBO-3 (1,1'-(4,4,7,7-tetramethyl-4,7-diazaundecamethylene)-bis-4-[3-methyl-2,3-dihydro-(benzo-1,3-thiazole)-2-methylidene]-pyridinium tetraiodide), and single-stranded homo-oligonucleotides, double-stranded complementary homo-oligonucleotides, and high-molecular-weight double-stranded polyhomonucleotides have been investigated in detail using absorption and both steady-state and time-resolved fluorescence spectroscopy. In this work, we describe the differences in the binding behavior of BOBO-3 with double-stranded DNA (dsDNA) having different base contents. The fluorescence intensity of BOBO-3 interacting with deoxyadenosine-deoxythymidine (dAdT) dsDNA was higher than with the deoxyguanosine-deoxycytidine (dGdC) double helix. However, the BOBO-3 lifetime was longer in dGdC-rich dsDNA than in dsDNA with many dAdT sites. This result was detected at both the ensemble level and the single-molecule level. This behavior is a consequence of the dye's interacting with dsDNA on two kinds of binding sites. This phenomenon also occurs in natural dsDNA (Ruedas-Rama, M. J.; Orte, A.; Crovetto, L.; Talavera, E. M.; Alvarez-Pez, J. M. J. Phys. Chem. B 2010, 114, 1094-1103). By using a time-resolved fluorescence methodology and the McGhee-von Hippel theory for two overlapping, noncooperative binding modes, we obtained the equilibrium binding constants and the number of occupied sites for each binding mode of BOBO-3 in dAdT and dGdC binding sites. BOBO-3 has a higher affinity for dAdT sites and occupies 4.0 +/- 1.0 sites in its primary binding mode, whereas in dGdC-rich double strands, BOBO-3 covers 6.2 +/- 1.1 sites and has a lower affinity. These differences in the binding features and spectral properties of BOBO-3 may be used to develop approaches to identify GC- or AT-rich regions within large strands of dsDNA.
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Affiliation(s)
- Maria J Ruedas-Rama
- Department of Physical Chemistry, Faculty of Pharmacy, University of Granada, Campus Cartuja, 18071 Granada, Spain
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162
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Ruedas-Rama MJ, Orte A, Crovetto L, Talavera EM, Alvarez-Pez JM. Photophysics and binding constant determination of the homodimeric dye BOBO-3 and DNA oligonucleotides. J Phys Chem B 2010; 114:1094-103. [PMID: 19994837 DOI: 10.1021/jp909863c] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The interactions between single- and double-stranded DNA and the trimethine cyanine homodimer dye, BOBO-3 (1,1'-(4,4,7,7-tetramethyl-4,7-diazaundecamethylene)-bis-4-[3-methyl-2,3-dihydro-(benzo-1,3-thiazole)-2-methylidene]pyridinium tetraiodide), have been investigated in detail using absorption and steady-state and time-resolved fluorescence spectroscopy. The dye interacts with both single-stranded and double-stranded DNA, under a variety of conditions, with changes in its spectral characteristics. Our results indicated that the complex formed between BOBO-3 dye and DNA oligonucleotides could not be explained with a simple, single intercalation mechanism; therefore, different modes of interaction were proposed. By using time-resolved fluorescence methodology and in-depth analysis of the fluorescence decay traces, we obtained the contribution of the different forms of BOBO-3: free in solution, a low affinity, electrostatically driven interaction with DNA, and a full bis-intercalation mechanism within the DNA double helix. With this information, we applied the McGhee-Von Hippel theory for two overlapping, noncooperative binding modes to obtain equilibrium binding constants and the number of sites occupied for each binding mode. Binding constants for dye/dsDNA complexes in complete bis-intercalation and externally bound were (8.8 +/- 1.1) x 10(5) and (2.6 +/- 0.3) x 10(5) M(-1), respectively. The corresponding recovered number of base pairs covered were 5.9 +/- 0.2 and 3.5 +/- 0.5 sites for each mode.
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Affiliation(s)
- Maria J Ruedas-Rama
- Department of Physical Chemistry, Faculty of Pharmacy, University of Granada, Campus Cartuja, 18071, Granada, Spain
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163
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Comparison of nine different real-time PCR chemistries for qualitative and quantitative applications in GMO detection. Anal Bioanal Chem 2010; 396:2023-9. [DOI: 10.1007/s00216-009-3418-0] [Citation(s) in RCA: 100] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2009] [Revised: 12/15/2009] [Accepted: 12/16/2009] [Indexed: 11/26/2022]
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164
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Ramalingam N, San TC, Kai TJ, Mak MYM, Gong HQ. Microfluidic devices harboring unsealed reactors for real-time isothermal helicase-dependent amplification. MICROFLUIDICS AND NANOFLUIDICS 2009; 7:325. [PMID: 32214955 PMCID: PMC7087983 DOI: 10.1007/s10404-008-0378-1] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2008] [Accepted: 11/18/2008] [Indexed: 05/11/2023]
Abstract
High-throughput microchip devices used for nucleic-acid amplification require sealed reactors. This is to prevent evaporative loss of the amplification mixture and cross-contamination, which may occur among fluidically connected reactors. In most high-throughput nucleic-acid amplification devices, reactor sealing is achieved by microvalves. Additionally, these devices require micropumps to distribute amplification mixture into an array of reactors, thereby increasing the device cost, and adding complexity to the chip fabrication and operation processes. To overcome these limitations, we report microfluidic devices harboring open (unsealed) reactors in conjunction with a single-step capillary based flow scheme for sequential distribution of amplification mixture into an array of reactors. Concern about evaporative loss in unsealed reactors have been addressed by optimized reactor design, smooth internal reactor surfaces, and incorporation of a localized heating scheme for the reactors, in which isothermal, real-time helicase-dependent amplification (HDA) was performed.
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Affiliation(s)
- Naveen Ramalingam
- BioMEMS Laboratory, N3.1, B3Ma, School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798 Singapore
| | - Tong Chee San
- School of Life Sciences and Chemical Technology, Ngee Ann Polytechnic, Block 83, #06-00, 535 Clementi Road, Singapore, 599489 Singapore
| | - Teo Jin Kai
- School of Life Sciences and Chemical Technology, Ngee Ann Polytechnic, Block 83, #06-00, 535 Clementi Road, Singapore, 599489 Singapore
| | - Matthew Yew Mun Mak
- School of Life Sciences and Chemical Technology, Ngee Ann Polytechnic, Block 83, #06-00, 535 Clementi Road, Singapore, 599489 Singapore
| | - Hai-Qing Gong
- BioMEMS Laboratory, N3.1, B3Ma, School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798 Singapore
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165
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Quantification of mitochondrial DNA (mtDNA) damage and error rates by real-time QPCR. Mitochondrion 2008; 9:31-5. [PMID: 19105983 DOI: 10.1016/j.mito.2008.11.004] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2008] [Revised: 11/10/2008] [Accepted: 11/21/2008] [Indexed: 01/05/2023]
Abstract
Mitochondrial dysfunction has reported in several diseases including diabetes, cancer, skeletal muscle disorders and neurodegenerative diseases such as Wolfram syndrome. Several different methods have evolved to study mtDNA damage including Southern blotting, 8-oxoG damage, or a comprehensive scanning of the mitochondrial genome by RFLP or TTGE analyses. However these approaches require large amounts of DNA or are labor intensive. The use of polymerase amplification of long DNA products (LRPCR) has been described by several groups and more recently summarized by Van Houten's group. The underlying basis use of DNA polymerases capable of generating long DNA products and the rationale is that any lesion (strand breaks, base modifications, apurinic sites) will stop a thermostable DNA polymerase. In this method, band density of the PCR product is quantified either by Southern blotting or binding of a fluorescent dye. Although the latter approach still has some limited use in the study gene expression, it is semi-quantitative and realtime PCR analysis has largely supplanted it. Direct application of real-time PCR to LRPCR has been made difficult because of low processivity and polymerization rates of the DNA polymerases used and SYBR green inhibition of DNA amplification. We have modified the LRPCR protocol to use the commercially available PfuUltra() II Fusion HS DNA Polymerase for real-time determination of mitochondrial DNA amplification as a means to simplify and improve of the accuracy for quantification of mtDNA damage.
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166
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Meng D, Lv DD, Fang J. Insulin-like growth factor-I induces reactive oxygen species production and cell migration through Nox4 and Rac1 in vascular smooth muscle cells. Cardiovasc Res 2008; 80:299-308. [PMID: 18567639 DOI: 10.1093/cvr/cvn173] [Citation(s) in RCA: 113] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
AIMS We showed previously that insulin-like growth factor-I (IGF-I)-induced vascular smooth muscle cells (VSMCs) proliferation through the production of reactive oxygen species (ROS). However, how IGF-I-induced ROS was unknown. The aim of this study is to investigate the mechanisms by which IGF-I induces ROS production in VSMCs. Methods results Reverse transcription-PCR, real-time PCR, immunoblotting, and confocal microscopic image analysis were employed to determine protein expression, small Rho-GTPase Rac1 activation, and ROS production. Inhibition of NADPH oxidase 4 (Nox4) or Rac1 was performed by means of siRNA technology. Inhibition of Rac1 activity was accomplished using dominant-negative form of Rac1 (N17Rac1) plasmid. VSMCs from Sprague-Dawley rat thoracic aortas were used in this work.IGF-I enhanced ROS production in rat VSMCs. IGF-I increased the protein level of Nox4 but had little effect on its mRNA level. IGF-I induced the activation of Rac1. Either knockdown of Nox4 or inactivation of Rac1 impaired IGF-I-induced ROS. Over-expression of Nox4 increased NADPH oxidase activity, which was not influenced by inactivation of Rac1. Neither over-expression nor knockdown of Rac1 influenced Nox4 expression. Knockdown of Nox4 did not affect IGF-I-induced activation of Rac1. IGF-I increased matrix metalloproteinase (MMP)-2 and 9 activity and promoted VSMC migration, which was inhibited by knockdown of Nox4 and inactivation of Rac1. CONCLUSION Our results suggest that Nox4 and Rac1 mediate IGF-I-induced ROS production and cell migration in VSMCs and that Nox4 is not regulated by Rac1.
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Affiliation(s)
- Dan Meng
- The Key Laboratory of Nutrition and Metabolism, Institute for Nutritional Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 294 Tai-Yuan Road, Shanghai 200031, People's Republic of China
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167
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Hernández-Arteaga S, López-Revilla R. Quantitation of human papillomavirus type 16 E6 oncogene sequences by real-time or quantitative PCR with EvaGreen. Anal Biochem 2008; 380:131-3. [PMID: 18539127 DOI: 10.1016/j.ab.2008.05.012] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2008] [Revised: 05/13/2008] [Accepted: 05/14/2008] [Indexed: 11/30/2022]
Abstract
Quantitation of E6 oncogene sequences of the human papillomavirus type 16 by real-time or quantitative PCR (qPCR) is used to determine the viral load, which correlates with the degree of the cervical neoplastic lesions. In the presence of EvaGreen, a new DNA intercalating fluorochrome, we obtained consistent and reproducible qPCR amplification curves and thermal denaturation profiles identical to those of the authentic E6-HPV16 (human papillomavirus 16) genome from the amplification products derived from a construct carrying the E6-HPV16 oncogene. E6-HPV16 quantitation in the presence of EvaGreen, therefore, is reproducible and specific and may be used to determine HPV16 viral load.
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Affiliation(s)
- Socorro Hernández-Arteaga
- División de Biologi a Molecular, Instituto Potosino de Investigación Cienti fica y Tecnológica, 78216 San Luis Potosi, Mexico
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