Degradation of SARS-CoV-2 specific ribonucleic acid in samples for nucleic acid amplification detection

The degradation of SARS-CoV-2 specific ribonucleic acid (RNA) was investigated by a numerical modeling approach based on nucleic acid amplification test (NAAT) results utilizing the SmartAmp technique. The precision of the measurement was verified by the relative standard deviation (RSD) of repeated measurements at each calibration point. The precision and detection limits were found to be 6% RSD (seven repeated measurements) and 94 copies/tube, respectively, at the lowest calibration point. RNA degradation curves obtained from NAAT data on four different temperatures were in good agreement with the first-order reaction model. By referring to rate constants derived from the results, the Arrhenius model was applied to predict RNA degradation behavior. If the initial RNA concentration was high enough, such as in samples taken from infected bodies, the NAAT results were expected to be positive during testing. On the other hand, if initial RNA concentrations were relatively low, such as RNA in residual viruses on environmental surfaces, special attention should be paid to avoid false-negative results. The results obtained in this study provide a practical guide for RNA sample management in the NAAT of non-human samples.