Journal: Scientific Reports

Article Title: A lyophilized colorimetric RT-LAMP test kit for rapid, low-cost, at-home molecular testing of SARS-CoV-2 and other pathogens

doi: 10.1038/s41598-022-11144-5

Figure Lengend Snippet: Limit of detection and validation of analytical sensitivity and specificity on virus-spiked anterior nasal swab collection media. ( a ) Serial dilutions of heat-inactivated SARS-CoV-2 strain WA-1/2020 by percent positive samples. Three independent replicates of four-reactions per dilution were performed using samples from 227 copies per reaction to 17,473 copies per reaction. X-axis is log-scale showing copies per reaction, Y-axis shows % positive reactions. Each data point shows the average and standard error of the mean (SEM) for each set of replicates per dilution. A Sigmoidal dose–response curve was fit using the Find ECAnything least squares fit in Graphpad Prism 7.0 with lower and upper limits of 0 and 100 respectively. Red-dotted lines and grey area indicates 95% confidence interval around the dose–response curve. Straight dotted lines show 50 and 95% analytic sensitivity intercepts as predicted by the fitted curve. 95% limit of detection was 15,514 viral copies, 50% limit of detection was 1421 viral copies per reaction. ( b ) 20 replicates of non-template control (NTC, anterior nasal swab media only; bottom panels) versus 15,518 viral copies of heat-inactivated SARS-CoV-2 (top panels) in uninfected pooled anterior nasal swab media, demonstrating ≥ 99% analytical specificity and ≥ 95% analytical sensitivity at 15,518 copies/reaction. Nuclease-free water non-template control (−) and BEI RNA positive control (+), indicated. Pre-incubation and incubation times and colorimetric changes as above.

Article Snippet: A Sigmoidal dose–response curve was fit using the Find ECAnything least squares fit in Graphpad Prism 7.0 with lower and upper limits of 0 and 100 respectively.

Techniques: Positive Control, Incubation