(A-F) Vero E6-TMPRSS2 (A, C, E) or Vero-E6 cells (B, D, F) were infected with SARS-CoV-2 WA1 at an MOI of 0.001. Supernatants were collected twice daily for two days, daily for an additional two days, and cells and supernatants were collected for a final time point at day 7 (for Vero E6-TMPRSS2 cells) or day 8 (for Vero E6 cells). A, B) Viral titer was determined by immune-focus forming assay (focus-forming units [FFU]/mL), day 0 values are calculated based on known titer of inoculum. RNA levels were determined by RT-PCR from cells (C, D) or viral supernatants (E, F) for each time point using the indicated primer-probe sets. Note that CT is plotted inversely on the Y axes, so that lower RNA concentrations are shown lower on the axes. All data points represent four technical replicates from two independent experiments and are plotted as mean with error bars plotted as +/- SEM. Limit of detection for infectious titer is plotted as the minimum y value. 