What is RT-PCR?

There are many mentions in the news about the use of "RT-PCR" as a laboratory assay for testing to determine the specific type of influenza virus(es). What is RT-PCR?

RT-PCR stands for Real-Time Reverse Transcription - Polymerase Chain Reaction. Note that it is a rapid ("Real-Time") assay (usually takes a few hours), but that the "RT" in "RT-PCR" related to this particular influenza situation stands for "reverse transcription."

A polymerase chain reaction (PCR) is a process whereby a tiny quantity of a specific DNA sequence is amplified into billions of copies. The purpose of doing this is to create a sufficient quantity for testing, such as determination of the sequence of amino acids that comprise that particular DNA. The exact method by which this occurs requires some recognition of the flanking (to the sequence to be amplified) amino acids, in order to prime the reaction.

PCR is accomplished with DNA. The genetic material of the influenza virus is RNA, so the viral RNA sequence must be transformed into a DNA sequence. This is accomplished with the enzyme "reverse transcriptase" (the "RT" in "RT-PCR").

The test is being used on samples (nasal swabs or other respiratory secretions) of persons who test positive for influenza A to determine whether or not they are infected with A (H1N1), rather than "seasonal flu."

Tags: A(H1N1) influenza, RT-PCR, influenza, swine flu, flu, swine influenza, wilderness medicine, outdoor medicine, healthline