Figure 2.

Verifying the sensitivity of the RT-LAMP for viral RNA. A. Sensitivity of the RT-LAMP using RNA ranging from 1 × 10¹¹ to 1 × 10⁰ copies as confirmed by the naked eye and 2% agarose gel electrophoresis. B. qRT-PCR positive amplification determined through its cycle threshold value in each RNA-dilution point. C. Determination of optimum reaction time of RT-LAMP for positive amplification that was assessed using the determined dilution limit of SARS-CoV-2 synthesized RNA. Observation of colour change from pink to yellow indicates positive nucleic acid amplification. The left panel shows the RT-LAMP reaction along with the electrophoresed RT-LAMP products for confirmation. (M, 100 bp ladder size marker and serially diluted viral RNA of 10–10,000 concentration of RNA copies). D. Limit of detection in ten repetitions using diluted RNAs (10³, 10², and 10¹). E. Comparative evaluation of time efficiency of RT-LAMP versus qRT-PCR. Lane M: 1000 bp DNA ladder; N.C: negative control, *: Limit of detection of qRT-PCR was evaluated using 10 repeats of 10³, 10², 10¹, and 100 diluted RNA and the results are shown in Supplementary Table 4.