[Rapid identification of SARS-CoV-2 main variants using real-time quantitative PCR assay]

A TaqMan probe real-time quantitative PCR (RT-qPCR) approach was developed for rapid identification of SARS-CoV-2 main variants. Specific primers and probes were designed based on the sequence of the SARS-CoV-2 wild and main variants alpha (N501Y, HV69-70del), beta (E484K, K417N), gamma (K417T, V1176F), delta (L452R, T478K) and omicron (H655Y, N679K, P681H) genes. The specificity, sensitivity and performance of the RT-qPCR assay were tested. The assay can identify SARS-CoV-2 wild type and main variants efficiently, and has no crossover with a panel of respiratory pathogens (n=21), showing high specificity toward SARS-CoV-2 RNA. The assay's sensitivity was determined to be 2×10² copies/mL. In summary, we developed a simple, rapid and cost-effective RT-qPCR assay that enables identification of SARS-CoV-2 main variants. It can be used to monitor the variation of SARS-CoV-2 strain for accurate identification, prevention and control of outbreaks.