Optimal stabilization for long-term storage of nucleic acid-based CRISPR/Cas12a assay for SARS-CoV-2 detection

In this long-term storage study, we optimized the lyophilization conditions of each reaction stage of a nucleic acid-based assay for SARS-CoV-2 detection. The stability testing demonstrated that the dried reactions from all 3 steps (cDNA synthesis, isothermal amplification and detection) can be kept at -20°C or 4°C for up to 6 or 3 months, respectively, whereas, if stored at 25°C or 37°C, the reagents only could be stored for a few days without quality loss. This suggests that we can have the dried reactions at -20°C for long-term storage until needed. Moreover, this assay is now simpler to perform as each of the 3 steps now proceeds with pre-mixed regents lyophilized in a single tube for each step.