Q.Corona Virus is a RNA virus. Basically PCR technique is used for detecting DNA. If so, how PCR technique is used for diagnosing Corona Virus ?
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Start your 14-day free trial to unlock the full solution →Corona virus RNA is first converted to cDNA by reverse transcriptase, and this cDNA is then amplified by PCR (making it RT-PCR) to detect the virus.
Standard PCR only amplifies DNA, so an extra step is needed to diagnose an RNA virus such as SARS-CoV-2. A nasal/throat swab sample is collected and the viral RNA is extracted. The enzyme reverse transcriptase is then used to synthesise a complementary DNA (cDNA) strand from this viral RNA template - this is the 'RT' (reverse transcription) step. The resulting cDNA is used as the template for PCR: specific primers that bind to conserved regions of viral genes (commonly the N gene, E gene, or ORF1ab region) are added along with Taq polymerase and nucleotides, and the cDNA is amplified through repeated cycles of denaturation, annealing, and extension. In the commonly used real-time RT-PCR (RT-qPCR), fluorescent probes bound to the amplified product emit a signal that is measured after every cycle; if the fluorescence cros …
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