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This technique is useful for numerous areas of research including gene expression analysis, genotyping, microRNA analysis, genetic variation analysis, and protein analysis. * * * ## Related Products Slide 1 of 9 1 of 2 [ \ Sigma-Aldrich \ STR1 \ Enhanced Avian First Strand Synthesis Kit](https://www.sigmaaldrich.com/CA/en/product/sigma/str1) Quick View [ \ Roche \ RNAINH-RO \ Protector RNase Inhibitor](https://www.sigmaaldrich.com/CA/en/product/roche/rnainhro) Quick View [ \ Sigma-Aldrich \ AMPD1 \ DNase I](https://www.sigmaaldrich.com/CA/en/product/sigma/ampd1) Quick View [ \ Sigma-Aldrich \ RDRT \ ReadyScript® cDNA Synthesis Mix](https://www.sigmaaldrich.com/CA/en/product/sigma/rdrt) Quick View [ \ Roche \ FSUPMMRO \ FastStart Universal Probe Master (Rox)](https://www.sigmaaldrich.com/CA/en/product/roche/fsupmmro) Quick View [ \ Roche \ FSUSGMMRO \ FastStart Universal SYBR Green Master (Rox)](https://www.sigmaaldrich.com/CA/en/product/roche/fsusgmmro) Quick View [ \ Roche \ FSSGMMRO \ FastStart SYBR Green Master](https://www.sigmaaldrich.com/CA/en/product/roche/fssgmmro) Quick View [ \ Roche \ FSTMPMMRO \ FastStart TaqMan® Probe Master](https://www.sigmaaldrich.com/CA/en/product/roche/fstmpmmro) Quick View [ \ Roche \ EAGLETMMRO \ EagleTaq Universal Master Mix (ROX)](https://www.sigmaaldrich.com/CA/en/product/roche/eagletmmro) Quick View * * * ## Featured Categories [](https://www.sigmaaldrich.com/CA/en/products/molecular-biology-and-functional-genomics/pcr-and-amplification/pcr-reagents-and-kits) [PCR Reagents & Kits](https://www.sigmaaldrich.com/CA/en/products/molecular-biology-and-functional-genomics/pcr-and-amplification/pcr-reagents-and-kits) Polymerase Chain Reaction (PCR) is a mainstay in molecular biology labs. PCR is used for amplifying DNA by several orders of magnitude and our reagents and resources are suitable for numerous research workflows including, gene expression analysis, genotyping, sequencing, and mutagenesis application needs. [Shop Now](https://www.sigmaaldrich.com/CA/en/products/molecular-biology-and-functional-genomics/pcr-and-amplification/pcr-reagents-and-kits) [](https://www.sigmaaldrich.com/CA/en/products/molecular-biology-and-functional-genomics/cloning-and-expression/molecular-cloning-and-protein-expression) [Molecular Cloning & Protein Expression](https://www.sigmaaldrich.com/CA/en/products/molecular-biology-and-functional-genomics/cloning-and-expression/molecular-cloning-and-protein-expression) Molecular cloning and protein expression methods and protocols for reliable cloning and robust protein expression from insect, bacteria, and mammalian protein expression vectors. 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[Shop Now](https://www.sigmaaldrich.com/CA/en/products/molecular-biology-and-functional-genomics/microbiome) Overview Related Articles & Protocols Support ## How to Analyze qPCR Data The fluorescence of the reporter molecules is measured and quantified; typically these are either dyes (i.e. SYBR® Green, Ethidium Bromide) that intercalate between the bases in double-stranded DNA, or probes designed to bind a specific sequence (i.e. Molecular Beacons, TaqMan® probes) on the DNA. ## Relative Quantitation of qPCR Data There are two major quantification methods for qPCR data. Relative quantification, the more common method, uses ΔΔCt information, by which the expression or abundance ratio of the target gene in the sample is determined, compared to a control gene, and normalized with the expression ratio of a reference gene. Since, the efficiency E values for target and reference genes differ, this method also accounts for the differences in E values. This method is more frequently employed in gene expression analysis. ## Absolute Quantitation of qPCR Data The second method, absolute quantification, is more common in environmental microbiology and makes use of the standard-curve (SC). The SC method uses dilution series of known template concentration, N0, to create a standard curve using the linear regression of log(N0) versus the CT (threshold cycle). This is then used to calculate template concentrations of the sample. The basis of this method is that the efficiency value of the sample is the same as that of the standard.  [Shop All qPCR Products](https://www.sigmaaldrich.com/search/facet-search?focus=products&page=1&perpage=30&sort=relevance&term=facet-search&type=product) [](https://www.sigmaaldrich.com/documents-search) ### [Looking for More Specific Information?](https://www.sigmaaldrich.com/documents-search) Visit our document search for data sheets, certificates and technical documentation. [Find Documents](https://www.sigmaaldrich.com/documents-search) ## Related Articles - [PCR/qPCR Data Analysis](https://www.sigmaaldrich.com/CA/en/technical-documents/technical-article/genomics/qpcr/data-analysis) After a traditional PCR has been completed, the PCR/qPCR data analysis is conducted by resolution through an agarose gel or, more recently, through a capillary. - [Quantitative PCR Basics](https://www.sigmaaldrich.com/CA/en/technical-documents/technical-article/genomics/qpcr/quantitative-pcr) Quantitative PCR detection builds on basic PCR techniques and allows researchers to estimate the quantity of starting material in a sample with a much wider dynamic range. - [PCR Assay Optimization and Validation](https://www.sigmaaldrich.com/CA/en/technical-documents/technical-article/genomics/pcr/assay-optimization-and-validation) PCR assay guide navigates you through primer validation and other assay optimization factors to ensure high sensitivity and specificity for optimum DNA/ RNA quantification. - [PCR/qPCR/dPCR Assay Design](https://www.sigmaaldrich.com/CA/en/technical-documents/protocol/genomics/pcr/pcr-qpcr-dpcr-assay-design) PCR workflow's variability influenced by sample source, reverse transcription, and assay design, impacting reproducibility. - [Hot Start PCR](https://www.sigmaaldrich.com/CA/en/technical-documents/technical-article/genomics/pcr/hot-start-pcr) The purpose of Hot Start PCR is to inhibit the PCR reaction in order to reduce nonspecific amplification, prevent the formation of primer dimers, and increase product yields. - [See All (34)](https://www.sigmaaldrich.com/CA/en/search/facet-search?focus=sitecontent&term=facet-search) ## Related Protocols - [Universal SYBR Green qPCR Protocol](https://www.sigmaaldrich.com/CA/en/technical-documents/protocol/genomics/qpcr/sybr-green-qpcr) Our SYBR Green qPCR Protocol is a method designed to detect accurate quantification of gene expression and RT-PCR reactions. - [ChIP-qPCR Data Analysis](https://www.sigmaaldrich.com/CA/en/technical-documents/protocol/genomics/qpcr/chip-qpcr-data-analysis) Chromatin Immunoprecipitation qPCR for studying gene regulation across conditions. - [Primer Concentration Optimization](https://www.sigmaaldrich.com/CA/en/technical-documents/protocol/genomics/qpcr/primer-concentration-optimization) Primer Concentration Optimization Protocol creates reaction matrix for testing primer concentrations against various partners. - [qPCR Efficiency Determination Protocol](https://www.sigmaaldrich.com/CA/en/technical-documents/protocol/genomics/qpcr/qpcr-efficiency-determination) Optimization of qPCR conditions is important for the development of a robust assay. The two main approaches are optimization of primer concentration and/or annealing temperatures. - [Multiplex Real-Time PCR](https://www.sigmaaldrich.com/CA/en/technical-documents/protocol/genomics/pcr/kapa-multiplex-rtpcr) Multiplex qPCR employing probe-based chemistries is a demanding application that often requires extensive optimization and validation. - [See All (28)](https://www.sigmaaldrich.com/CA/en/search/facet-search?focus=sitecontent&term=facet-search) ### Find More Articles and Protocols Enter Keywords Search ## How Can We Help In case of any questions, please submit a [customer support request](https://www.sigmaaldrich.com/CA/en/support/customer-support) or talk to our customer service team: Email [custserv@sial.com](mailto:custserv@sial.com) or call +1 (800) 244-1173 ## Additional Support - [Calculators & Apps](https://www.sigmaaldrich.com/CA/en/support/calculators-and-apps) Web Toolbox - science research tools and resources for analytical chemistry, life science, chemical synthesis and materials science. - [Customer Support Request](https://www.sigmaaldrich.com/CA/en/support/customer-support) Customer support including help with orders, products, accounts, and website technical issues. - [FAQ](https://maestro.my.site.com/knowledgeportal/s/) Explore our Frequently Asked Questions for answers to commonly asked questions about our products and services. * * * __Featured Articles__ [PCR/qPCR Data Analysis](https://www.sigmaaldrich.com/CA/en/technical-documents/technical-article/genomics/qpcr/data-analysis) After a traditional PCR has been completed, the PCR/qPCR data analysis is conducted by resolution through an agarose gel or, more recently, through a capillary. [Quantitative PCR Basics](https://www.sigmaaldrich.com/CA/en/technical-documents/technical-article/genomics/qpcr/quantitative-pcr) Quantitative PCR detection builds on basic PCR techniques and allows researchers to estimate the quantity of starting material in a sample with a much wider dynamic range. [RT-qPCR – Quantitative Reverse Transcription PCR](https://www.sigmaaldrich.com/CA/en/technical-documents/technical-article/genomics/qpcr/rt-qpcr) RT-qPCR detects specific targets with applications in gene expression and pathogen detection. [How qPCR Works](https://www.sigmaaldrich.com/CA/en/technical-documents/technical-article/genomics/qpcr/how-qpcr-works) Watch these videos to learn how real time or quantitative PCR (qPCR) works and the benefits of both the SYBR Green-based and probe-based methods of qPCR assay. Top __Sign In To Continue__ To continue reading please sign in or create an account. 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