Context: Recently, the Indian Council of Medical Research (ICMR) has approved a made-in-India testing kit, named Omisure, for detecting the Omicron variant of the SARS-CoV-2 coronavirus.
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.