By nucleic acid testing, we can know whether someone is infected with COVID-19 or not.
COVID-19 is a kind of RNA virus, nucleic acid testing is for detecting the RNA of COVID-19 virus by the technology of reverse transcription polymerase chain reaction. By this method, the RNA of COVID-19 can be translated into DNA and using PCR amplification for detecting DNA.
The nucleic acid testing first use disposal sample collector for oropharyngeal sampling or nasopharyngeal sampling. The inspector will use chemical solutions to remove protein, fat and other things from the sample, only the RNA is retained. If the subjects is infected with COVID-19, there will also with RNA of COVID-19 in it. Because the RNA sequence of the virus is unique, so scientist designed prime (the DNA fragments for identifying RNA) for testing. If there is no RNA of COVID-19 in the sample, nothing will be synthesized, and if there is, the primers will stretch out and, with the help of RNA reverse transcriptase, synthesize DNA strands that match specific RNA sequences. The RNA is then separated from the DNA, the other end of the primer is attached to the DNA, and another DNA polymerase is used to synthesize a strand of DNA. One strand of RNA is then reversed into a double strand of DNA, which is proof that a virus exists.
Because it is difficult to detect, PCR (polymerase chain reaction) is needed, which allows DNA fragments to be amplified rapidly and in large quantities in vitro, with the initial nucleic acid sequence being amplified several times. A fluorescent probe detection is used to detect a fluorescent signal, indicating positive COVID-19.
Now, RNA sample, primer, reverse transcriptase, DNA polymerase, and fluorescent marker are commonly put into PCR tubes. By using the PCR gene Amplification instrument, you can wait about three hours to get the nucleic acid test of the sample.