Figure 3.

Recovery of infectious SARS-CoV-2 virus from all surfaces of substrates. The infectious titers of SARS-CoV-2 were measured as TCID₅₀/mL in triplicate at 0, 3, 6, 12, and 24 h after inoculation, using VeroE6/TMPRSS2 cell cultures in 96-well plates. Samples at 0 h were measured immediately after drying. The left and right y-axes indicate infectious titer (log₁₀ TCID₅₀/mL) and RNA copy number (log₁₀ RNA copies/mL) of the virus, respectively. The closed red and open blue rhombuses indicate the mean titers and RNA copy number of the inoculated virus, respectively. The closed and open circles indicate the mean titers of the measured infectious titers and mean RNA copy numbers of virus, respectively. The cross marks indicate no-detection (ND) in triplicate. When calculating a mean value, ND was regarded as 0 TCID₅₀/mL. Horizontal thin and dotted lines mean limit of detection of the assays (LoD) at 0.6 log₁₀ TCID₅₀/mL for virus titer and 4.8 log₁₀ RNA copies/mL for RT-PCR, respectively. The numbers in parentheses beside the points including the data below LoD indicate the number of times above LoD in triplicate. The bars indicate the standard deviations of inoculated or collected virus. The break lines and thick lines indicate the declining rate of virus, calculated using linear regression.