The Indian Council of Medical Research (ICMR), here on Tuesday, asked states to stop the use of rapid testing kits of Covid-19 for at least two days as they were giving inaccurate results.

ICMR Chief Scientist Raman Gangakhedkar said, "We had received complaints from one state on Monday. On Tuesday, we asked two more states if they also experienced the problem. The difference in results of RT-PCR positive samples is huge, 6 to 71 per cent, at some places. We have advised states to halt its use for two days."

A lot of variations were observed in results of positive samples, tested by RT-PCR which was not good, he said and added, the ICMR would be in a position to give any advisory in at least two days.

The reverse transcription polymerase chain reaction (RT-PCR) is a laboratory technique combining reverse transcription of RNA into DNA and amplification of specific DNA targets using polymerase chain reaction (PCR).

The kits would be tested and validated by the on-ground teams instead of labs as Covid-19 was a new disease and the testing kits required to be refined, he said.

"We will deploy teams of our 8 institutes for on-ground validation of kits. If problems were found, those batches of kits would be sent to the manufacturing company for replacement," Gangakhedkar said.

The ICMR has received 500,000 rapid test kits from two Chinese companies - Guangzhou Wondfo Biotech and Zhuhai Livzon Diagnostics.

When West Bengal accused the ICMR of sending faulty kits, it refuted the charges saying the kits should be stored below 20 degrees Celsius temperature to get accurate results. It also said if the variation in results was not big then there was no need to worry.

But now the ICMR has said any new observation about the testing kits would not be taken lightly and would be cross-checked thoroughly (IANS)