Time to get report determines price of RT-PCR & rapid tests

Mumbai: The cost difference between the regular RT-PCRand the ‘Rapid RT-PCR’ tests at airports is due to the time factor. The RT-PCR test, costing Rs 600, gives a report within 5 hours, rapid tests take 5 minutes to 2 hours.

“The appropriate term,” said a civic hospital doctor, “would be rapid tests instead of rapid RT-PCR tests.” One test offered at Mumbai airport is US healthcare major Abbott’s ID test that gives positive result in 6 minutes.

Technically, PCR (polymerase chain reaction) and isothermal nucleic acid amplification technique (used in Abbott’s ID Now) are distinct, but both detect molecules — RNAs, DNAs and proteins. But PCR is still considered most accurate. Another test at the airport is cartridge-based nucleic acid amplification test (CBNAAT) that takes 2 hours.

Dr Nilesh Shah of Metropolis Lab said, “In a usual RT-PCR test, a laboratory is necessary. A technician has to collect the sample, manually extract the RNA and then place it in the PCR machine. The rapid tests have replaced the need for a laboratory as the whole process is replicated in a tiny box.” A rapid test contraption could be as small as a toaster.

Dr A Velumani, who founded Thyrocare Lab, said the rapid Covid tests emerged in the past year. “Unfortunately, the rapid term has allowed companies to skirt the government’s price control measures,” said Velumani. Rapid tests costs between Rs 3,000 and Rs 5,000.

Another doctor said a cartridge of CBNAAT test costs Rs 2,500. “One test requires one cartridge. So how much further can one reduce the test costs?” TNN