Coronavirus cases are increasing rapidly in the world. There are various doubts in the minds of people about the coronavirus, such as how to test the coronavirus and how does it happen?
What is the diagnostic test done for the coronavirus?
The Indian Council of Medical Research (ICMR) says that the polymerase chain reaction (PCR) test is conducted in a well-known lab. These PCR tests are performed on swabs of the throat, respiratory fluid, and mouth saliva samples. Such tests are usually performed to detect influenza A, influenza B, and H1N1 viruses.
According to doctors, the back of the nose and throat are the two places where the virus is more likely to be present. These cells are picked up through swab. The swab is inserted into a solution from which cells are released. The swab test is used to match the genetic material found in the sample to the genetic code of the coronavirus.
What is the PCR test?
It uses a technique that makes copies of DNA. ‘Polymers’ are those enzymes that make copies of DNA. In ‘chain reaction,’ DNA fragments are copied rapidly – like one is copied into two, two is copied into four and so on, this sequence continues. SARS-COV-2 virus is made up of RNA, so it needs to be converted into DNA. For this, a technique called reverse transcription is used. The ‘reverse transcriptase’ enzyme converts RNA into DNA. After this, copies of DNA are made and amplified.
‘Probe,’ which makes these DNA colorful, tells about the presence of the virus. This test also distinguishes SARS-COV-2 from other viruses.
How long does the PCR process take?
ICMR scientist Dr. RR Gangakhedkar says that this process used to take 6 hours at first, but real-time PCR has reduced the time taken to test the samples by 4 hours.
Dr. Gangakhedkar said, ‘However, the total time it takes to take samples and report is about 24 hours. Sometimes it can be less than that.
How is this test being done in India?
Senior Professor Dr. V Ravi told that two-stage real-time PCR is being done to test SARS-COV-2 in India. In the first stage, common genetic elements of the coronavirus are detected, which can be found in the sample.
The second stage tests specific genes that are present only in the SARS-COV-2 virus.
Dr. Ravi told that till the beginning of March, any coronavirus was being tested in every lab, but PCR was being done only by Pune’s National Institute of Virology for confirmation.
Dr. Ravi said, ‘NIV (National Institute of Virology) Pune has now sent this technique to all the labs so that there is no need to go to Pune to test the sample. This has also reduced the time taken to examine the sample.
10,000 sample tests can be done daily in India. Coronavirus tests are being done at 52 centers across the country.