Fig. 2.
Furin cleavage site deletion increases S pseudovirus entry. A. HEK293T cells transiently expressing SARS-CoV-2 S mutant variants were incubated with the anti-SARS-CoV-2 spike antibody on ice. Cells have analyzed the expressions by flow cytometry. B. The infection efficiency of SARS-CoV S different variants in the similar virus harvest supernatant titers (Scale bar = 100 µm). EGFP fluorescence intensity was detected using the FITC channel (527/32 filter) by flow cytometry (SFL-negative control, VSV-G-positive control). C. Transduction efficiency of different six types of cells was tested for S variants PVs. The y-axis showed the luciferase activity (Log10) value detected 48 h after infection with SARS-CoV S different variants. The experiments were repeated at least three times.