Fig. 4: SHERLOCK detection of SARS-CoV-2 in 154 nasopharyngeal and throat swab clinical samples.
From: Clinical validation of a Cas13-based assay for the detection of SARS-CoV-2 RNA
Positive COVID-19 clinical samples were binned according to their Ct values from RT–qPCR, with the total number of clinical samples in each Ct bin shown. Representative lateral-flow and fluorescence detection are shown for each Ct bin as well as for negative COVID-19 samples. The full dataset is shown in Supplementary Fig. 4. For the lateral-flow readout, the appearance of a coloured test band, often in conjunction with the disappearance of a coloured control band, indicated a positive COVID-19 result. Quantification of band intensities is shown in Supplementary Fig. 4. For the fluorescence readout, we set the threshold (blue line) of signal-to-noise (S/N) of fluorescence intensities (with noise being the fluorescence intensity from a negative sample with water as input performed in parallel) for a positive result to be 2. Bottom rows show the numbers of false-negative samples; rates of false-negative results are shown for each Ct bin and for the two SHERLOCK readout modes.
