OmiSure RT – PCR Kit

The Indian Council of Medical Research (ICMR) recently approved ‘OMISURE’. Omisure is a RT – PCR kit. It is used to detect Omicron, a  COVID-19 variant. It was manufactured by Tata Medical and Diagnostics.

About the kit

The kit was designed and developed by a US – based company Thermo Fisher. It was manufactured by Tata. The kit uses S Gene Target Failure to detect Omicron. It is currently the only kit in India to use this method to detect Omicron. The price of the kit is Rs 240. The cost of RT – PCR kits sold by government agencies is Rs 20 to Rs 30.

S Gene Target Failure

S gene is Spike gene of COVID -19 virus. The mutation in this gene deletes amino acids 69 and 70. This mutation helps them escape RT – PCR test. A kit or test that catches this gene deletion in COVID-19 variants are generally referred to as the S Gene Target Failure kits or S gene drop detection kit.

Omicron and S gene

The S Gene target failure or S gene drop out is one of the prominent indicators to establish the presence of Omicron. In India, the COVID tests screen for Rd, Rp, E and N genes. Even if one of these genes are found, the test result is positive for COVID-19. So far S gene test was not conducted in the country as there was no requirement for it.

Does the kit work against Omicron like variant?

Recently, C.36.3.1 was detected. It carries Omicron like genetic variation. S – gene drop out has been identified in this new variant. It carries 36 mutations. Of these 9 mutations are in S gene. On the other hand, Omicron carried 52 mutations and of these 32 were identified in S gene. It is neither a variant of concern nor a variant of interest. The company is still testing if the kit will work for other Omicron like variants.



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