File:Fig1 Pickering LancetMicrobe2021 2-9.jpg

Figure 1. Comparative sensitivity of six commercial SARS-CoV-2 rapid antigen tests. (A) Heatmap comparison of lower limit of detection. (B) Association between PFUs/mL and Ct result from qRT-PCR for the SARS-CoV-2 N gene (N Ct value). Error bars represent SD of three independent experiments. (C) Association between RNA copy number and N Ct values. Copy number per mL was derived from N qRT-PCR on the Zeptometrix RNA standard (consisting of purified, inactivated viral particles of known RNA copy number per mL). In (B) and (C), points were fitted with a linear regression, with the equation of the line and the R² value shown. Horizontal dashed lines denote Ct values of 25 and 28, as the threshold cutoffs used for sensitivity determinations. (D) Tests were evaluated in head-to-head comparisons on a panel of 100 SARS-CoV-2-positive nasopharyngeal swabs. Bars denote the N Ct result for each swab, in ascending order, with the antigen test results for each sample directly below each bar presented as a heatmap. Sensitivity determinations from this sample set are shown on the right. Ct value cutoffs of 25 and 28, corresponding to 1.49 × 106 and 1.65 × 105 RNA copies per mL, or 400 and 50 PFUs/mL, respectively, are indicated, with corresponding sensitivity values for each test at each threshold on the right. PFU = plaque-forming unit; SureScreen-F = SureScreen fluorescent; SureScreen-V = SureScreen visual; N = SARS-CoV-2 nucleocapsid; Ct = cycle threshold; qRT-PCR = real-time RT-PCR.

Pickering, S.; Batra, R.; Merrick, B. et al. (2021). "Comparative performance of SARS-CoV-2 lateral flow antigen tests and association with detection of infectious virus in clinical specimens: A single-centre laboratory evaluation study". The Lancet Microbe 2 (9): e461-e471. doi:10.1016/S2666-5247(21)00143-9. 

2021

Pickering, S.; Batra, R.; Merrick, B. et al.

Creative Commons Attribution 4.0 International