Welcome to our discussion on the electrochemical detection of COVID-19 using reverse transcription polymerase chain reaction (PCR).


Though PCR is entering the widely used lexicon it is not always understood; a simple definition of PCR is a method by which DNA can be amplified so that it can subsequently detected or measured. The term amplification in this context means that the amount of DNA is increased (multiplied) by the polymerase chain reaction.


There is a hyphenated version of PCR, which is relevant when discussing COVID-19, this is real time PCR, also known as quantitative PCR (qPCR). In qPCR it is possible to measure the amount DNA as a function of time/cycles.  The time it takes for DNA to be detected is proportional to the amount of target DNA in the original sample and so the real-time PCR/qPCR can be a quantitative.


Of course, COVID-19 a virus and hence has RNA as opposed to DNA. Therefore, when you look at the tests on the market for the detection of an active COVID-19 infection many are best described as RT-PCR, where the RT stands for reverse transcriptase. The sequence of events in a COVID-19 RT-PCR is that the COVID-19 RNA first undergoes transcription from RNA to DNA, and subsequently the DNA is amplified (multiplied) and in real time the amplification of the DNA is measured.