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.