While real-time PCR is designed for amplification of DNA, using a reverse transcriptase enzyme (RTE) allows amplification from an RNA target by creating a copy of DNA from the original RNA molecule. The PCR process is modified for the amplification of RNA by the addition of a RTE in the assay components. RTE creates a copy of DNA using the original RNA specimen. Although there are thermostable polymerases that have reverse transcriptase capabilities, they are not commonly used.
Reverse transcriptase PCR (RT-PCR) is used for the detection of viruses, such as HIV, hepatitis C virus (HCV), and Influenza, that have an RNA genome. Reverse transcriptase PCR methods provide early detection of infection, even before the formation of antibodies. Therefore, it is a particularly useful method for HIV and HCV detection in blood bank nucleic acid testing.
Reverse transcriptase PCR (RT-PCR) is commonly performed using the real-time PCR method.