It was the beginning of a revolution in Molecular biology in 1983 when Kary Mullis first introduced the concept of in-vitro amplification of DNA with a polymerase enzyme. Since then, several advances and derivations of this method has lead to numerous applications in molecular biology.
Real time PCR (qrt-PCR – Quantitative Real Time PCR) is one such PCR based method that actually incorporates amplification and simultaneous quantification of amplicons. During conventional PCR, the product is detected at it’s end but with qrt-PCR the product is detected during the progress of the reaction. The really useful application of PCR relies on quantification of m-RNA, in which qrt-PCR is coupled to reverse transcriprase PCR.