Quantitative real-time PCR-based analysis of gene expression.

Quantitative real-time polymerase chain reaction (QRT-PCR) has become an extensively applied technique. It enables quantitative analyses of gene expression applicable to basic molecular biology, medicine, and diagnostics. Nowadays, it is broadly used to describe messenger RNA (mRNA) expression patterns and to compare the relative levels of mRNA within distinct biological samples. The scope of the QRT-PCR technique makes it applicable across a wide range of experimental conditions and allows experimental comparison between normal and abnormal tissue. Most importantly, this technique enables additional independent confirmation of microarray or next generation sequencing (NGS)-based results. An inherent advantage of QRT-PCR is the large dynamic range, remarkable sensitivity, and sequence-specificity. We provide a detailed step by step guide to the principles underlying a successful QRT-PCR experiment.