Fig. 1.

Ct value for ORF1ab and N genes of four cryogenic disinfectants on SARS-CoV-2 inactivation at − 20 °C at different time point. As shown in Figure, Ct value showed the ORF1ab and N genes of SARS-CoV-2 nucleic acid tested result by qRT-PCR, which were inactivated by peracetic acid (PA), trichloroisocyanuric acid (TA2000, available chlorine 2000 mg/L), trichloroisocyanuric acid (TA1000, available chlorine 1000 mg/L) and Di-N-decyldimethylammonium chloride (DNC) with their own antifreeze at − 20 °C from 5 to 180 min. Plots show the means and standard error (I bars) across three replicates. The dashed lines indicate the Ct value of the positive control, which were 19.7 ± 0.2 per carrier (ORF1ab) and 23.0 ± 0.0 per carrier (N) for these four cryogenic disinfectants, respectively