From Figure 1:
Infectiousness was determined for a subset of N1 Ct-matched specimens with Ct <25 by inoculation onto Vero E6 TMPRSS2 cells and determining presence of cytopathic effects (CPE) after 5 days in culture.
In Laymens terms: they didn't check for viruses. They just looked to see if the cells got fucked up. And they did this check using the CDC's N1 primer set (the same primer set authorized under EUA last year. Zero. Independent. Science.
From Figure 1: Infectiousness was determined for a subset of N1 Ct-matched specimens with Ct <25 by inoculation onto Vero E6 TMPRSS2 cells and determining presence of cytopathic effects (CPE) after 5 days in culture.
In Laymens terms: they didn't check for viruses. They just looked to see if the cells got fucked up. And they did this check using the CDC's N1 primer set (the same primer set authorized under EUA last year. Zero. Independent. Science.