Question

1. What is RT-PCR?

2. What is quantitative or “real-time” PCR?

3. Why is there a need to reverse transcribe the viral genome? (what is the viral genome of SARScov-2)

4. Why is qRT-PCR the gold-standard for the detection of the SARS-Cov-2 virus? (compared to rapidtest kits)

Answer 1

Ans ) 1. RT- PCR is Reverse transcription polymerase chain reaction. It is a technique to amplify the specific DNA targets by converting RNA into cDNA using reverse transcription followed by Polymerase chain reaction. The amplification reaction is monitored using flourescence.

2. Real time PCR or qPCR is a technique to measure gene expression. It monitors the amplification of the reaction and collects the data as the reaction is measured. PCR products are detected or monitored using fluorescent dyes or fluorescent labelled DNA probes.

3. The viral genome, mainly on case of SARScov- 2 is a single strand RNA. So to amplify it's genome, the RNA first needs to be converted into DNA using Reverse transcriptase enzyme. The process is called reverse transcription.

4. qRT - PCR helps in testing SARS-CoV-2-infected individuals during the acute phase of infection. Since RT-PCR has the ability to amplify a tiny amount of viral genetic material in a sample and give results in less time, it is considered to be the gold standard for identification of SARS-CoV-2 virus.Rapid testing kits, on the other hand, are based on based either on detection of proteins from the virus in the samples or detection of human antibodies generated in response to infection. They may sometimes give false positive or false negative results and can give results only when the infection has been established.