Fig. 4.

S gene detection designs and characterization for variants of concern. (a) Designed detection sets for differentiation and identification of SARS-CoV-2 Alpha variant, B.1.1.7 and Beta variant, B.1.351. Design was based on sequence differences in the S gene between the variants. (b) List of primers and probes sequences for variants detection. (c) Calibration curves for primers-probe sets for variants of concern detection. Resulted Ct value from RT-qPCR plotted against Log copy number tested. Error bars present standard deviation for six replicates. (d) List of Limit of detection, Linear regression R², and Y intercept values extracted from the resulted calibration curves. (For interpretation of the references to color in this figure legend, the reader is referred to the Web version of this article.)