COVID-19 Test: ICMR releases revised guidelines for COVID-19 testingIndian Council of Medical Research (ICMR) has released revised guidelines for TrueNat, a comprehensive assay for screening and testing for positive cases for COVID-19, on Tuesday. New Delhi: Indian Council of Medical Research (ICMR) has released revised guidelines for TrueNat, a comprehensive assay for screening and testing for positive cases for COVID-19, on Tuesday. Step 2 is called RdRp gene confirmation assay, and if the sample tests positive through this it must be considered as true positive. As for the negative samples, they must be considered as true negatives. No further testing is needed for them, it said.24,04,267 samples have been tested as per the ICMR data, last updated on May 19, 9 am IST.