Sree Chitra Tirunal Institute for Medical Sciences and Technology (SCTIMST) has developed a multiplex RT-PCR kit that has a higher accuracy of detecting Covid-19 across the various mutant strains.

Second wave woes

As the pandemic is seeing a second wave with multiple variants, the selection of target genes in multiplex RT-PCR assay is becoming critical for accurate detection of the virus, said an official statement on Tuesday.

“Even though coronaviruses make far fewer errors than other RNA viruses, the mutations in S, R, and N genes often interfere with RT-PCR assay. For example, the variant of concern B1.1.7 (also known as the UK variant) has a 69-70del, due to deletion of 6 bases in the RNA, which resulted in S gene drop out from RT-PCR assay,” it said.

The new SCTIMST multiplex RT-PCR kit, on the other hand, targets two SARS CoV2 genes – RdRp and ORFb-nsp14 – and the human RNAse P gene as the internal control to help detect a range of mutant strains.

Various studies have shown that RdRp and ORFb-nsp14 genes are more sensitive in detecting Covid.

In order to target the multiple variants in the second wave, using two highly accurate confirmatory genes such as RdRp and ORFb-nsp14 can give precise results. The ORFb-nsp14 is one of the least mutated genes in Covid, and currently there are no kits in the market with ORFb-nsp14 as the target.

Kit validated

The kit, which has been validated by Indian Council of Medical Research’s National Institute of Virology in Pune, has been given to Hyderabad-based firm Huwel Lifesciences for commercialisation on a non-exclusive basis, said the statement.