Digital PCR vs. Real-Time PCR

We often receive questions related to the differences between Real-Time PCR and Digital PCR so we've taken some time to write this blog post accompanied by the poster pictured on the left. This poster is a great visual reference that illustrates the differences between the two methods.

Click here to view or download the full size poster for free

Real-Time PCR—also called quantitative polymerase chain reaction (qPCR)—is one of the most powerful and sensitive gene analysis techniques available and is used for a broad range of applications including quantitative gene expression analysis, genotyping, SNP analysis, pathogen detection, drug target validation and for measuring RNA interference. Frequently, real-time polymerase chain reaction is combined with reverse transcription to quantify messenger RNA (mRNA) and MicroRNA (miRNA) in cells or tissues.

As the name suggests, real-time PCR measures PCR amplification as it occurs. This completely revolutionizes the way one approaches PCR-based quantitation of DNA and RNA. In traditional PCR, results are collected after the reaction is complete, making it impossible to determine the starting concentration of nucleic acid.

Digital PCR is a new approach to nucleic acid detection and quantification, which is a different method of absolute quantification and rare allele detection relative to conventional qPCR, because it directly counts the number of target molecules rather than relying on reference standards or endogenous controls.