Fig. 2

SYBR green detection of extracted RNA. a Serial dilutions of SARS-CoV-2 synthetic RNA standards (Twist Biosci) were run in SYBR green and BGI TaqMan assays. Mean ± STD; n ≥ 3. b Comparison of Ct values obtained for each patient sample with the SYBR green and BGI TaqMan assays. BGI data is from Fig. 1b, c. c Amplification cures for four additional positive and 30 negative patient samples using SYBR green and the SH-N1 primers. d Example melt curves from a synthetic Twist SARS-CoV-2 RNA standard (std), high-level positive sample (P7) or two low-level positive samples (P6 and P33) (top) or two negative patient samples (N3 and N9) (bottom). e Melt temperatures (Tm) of the two high-level positive samples (H, P7 and P35), two low-level positive samples (L, P6 and P33) and 30 clinical negative samples (N1–N30). Dotted lines indicate acceptable range for a positive Tm (synthetic SARS-CoV-2 RNA ± 0.5 °C)