Human DNA does not produce a positive result on the RT-PCR test for SARS-CoV-2
The reverse-transcription PCR (RT-PCR) test is the method of choice for detecting SARS-CoV-2 in samples and is highly specific for the virus. For a PCR test to successfully amplify nucleic acids (DNA or RNA) in a sample, it is necessary for a pair of primers, which are short sequences of single-stranded nucleic acids that recognize and bind to a specific region of the genome, to flank the same target sequence. If only one primer in the pair is able to do so, amplification does not take place and the test produces a negative result. Therefore, even when an RT-PCR test for SARS-CoV-2 uses a primer that matches a human gene sequence, the test would not produce a positive result with human DNA alone because the other primer does not match the human gene sequence.