As the pandemic is going through a second wave with multiple variants, a multiplex RT-PCR kit has been developed that has a higher accuracy of detecting various mutant strains of the deadly coronavirus. The newly designed kit has been developed by the Sree Chitra Tirunal Institute for Medical Sciences and Technology under the Department of Science and Technology.

What

  1. ICMR has validated this kit at the National Institute of Virology, Pune, and found that it has 97.3% sensitivity and 100% specificity in covid19 detection.
  2. The new multiplex RT-PCR kit targets two SARS CoV2 genes namely RdRp and ORFb-nsp14, and the human RNAse P gene as the internal control to help detect a range of mutant strains.
  3. Various studies have shown that RdRp and ORF1b-nsp14 genes are more sensitive in detecting Covid19. In order to target the multiple variants in the second wave, using two highly accurate confirmatory genes like RdRp and ORF-nsp14, can give precise results.
  4. The ORFb-nsp14 is one of the least mutated genes in Covid19 and currently, there are no kits in the market with ORF-nsp14 as the target.
  5. The new kit is based on multiplex Taqman chemistry, amplifying all three genes in a single reaction. The amplification time for the assay is 45 minutes, apart from the time required for the RNA isolation from nasopharyngeal swab samples.
  6. Multiplexing two confirmatory genes will help shortlist possible new variants if one of the genes fails to amplify and can be marked for sequence analysis.