Fig. 1
From: Screening and confirmation tests for SARS-CoV-2: benefits and drawbacks
Adapted from Xu et al. [32]
Schematic illustration of RT-PCR. Before RT-PCR is performed, the sample obtained from a tested individual is subsequently subjected to a lysis reaction and RNA purification to extract the viral RNA. If the targeted viral RNA is present, the specific primer binds to a complementary region of the RNA, and reverse transcriptase generates the first-strand complementary DNA (cDNA) using the viral RNA template. Then, PCR cycle at different temperatures to separate the DNA strands (including the first-strand cDNA) allows binding of DNA primers to the template DNA and then allows DNA polymerase enzyme to extend the new DNA strand. Ultimately, this creates more copies of the double-stranded DNA (dsDNA) that allow detection of the viral nucleotide.