Fig. 6: Detection of influenza A virus with the SURVEY method.

a–c LoD analysis for the synthetic M2 protein coding gene (DNA) using the RPA-Cas12a one-pot detection method without (a) and with (b) 40 µg/mL heparin sodium, and qPCR (c) at target concentrations of 0, 0.1, 1, 10, 100, 1000, 10000 aM. d–f LoD analysis for transcribed mRNA targets using the RT-RPA-Cas12a one-pot detection method without (d) and with (e) 10 µg/mL heparin sodium, and RT-qPCR (f) at target concentrations of 0, 0.1, 1, 10, 100, 1000, 10000 aM. g Schematic representation of detection of human saliva and sputum samples. h Analysis of samples from all 33 patients using RT-qPCR and the SURVEY method. RT-qPCR was performed for 40 cycles. For SURVEY detection, the threshold was set to the negative control fluorescence value plus three times its standard deviation; samples exceeding this threshold were classified as positive, while those below were considered negative. i Specificity and sensitivity analysis for samples detection using the SURVEY method, with RT-qPCR serving as the gold standard for determining negative and positive results. Data are shown as mean ± s.d. for n  =  3 biologically independent samples. Statistical significance was analyzed using a two-tailed t test: ns, p > 0.05. The schematics shown in Fig. 6g were created by figdraw.com.