2.3 Nucleic Acid Detection of SARS-CoV-2
All RNA samples were identified with nucleic acid detection of
SARS-CoV-2 using real-time RT-PCR based on the recommendation by the
China CDC (http://ivdc.chinacdc.cn /kyjz/202001/t20200121_211337.html).
Briefly, two target genes, including nucleoprotein (N) gene and open
reading frame (ORF) 1ab, were simultaneously amplified and tested during
the real-time RT-PCR assay. Target 1 (N): forward primer
GGGGAACTTCTCCTGCTAGAAT; reverse primer CAGACATTTTGCTCTCAAGCTG; and the
probe 5′-FAM-TTGCTGCTGCTTGACAGATT-TAMRA-3′. Target 2 (ORF1ab): forward
primer CCCTGTGGGTTTTACACTTAA; reverse primer ACGATTGTGC ATCAGCTGA; and
the probe 5′-VIC-CCGTCTGCGGTATGTGGAAAGGTTATGG-BHQ1–3′. The criteria for
confirmed diagnosis of SARS-CoV-2 were that both two genes amplified to
be positive for N and ORF 1ab gene.