Extended Data Figure 2. ΔPRRA mutant processing and competition with WT.

A) Quantitation by densitometry of the full-length spike (Black) and S1/S2 cleavage form (Gray) from distinct western blot experiments in Vero E6 cells (n=2). B) Schematic of quantitative RT-PCR approach to detect deletion of the furin cleavage site. C) Primer curve validation with mixed WT to ΔPRRA plasmid ratio showing sensitivity. D) Deep sequencing results from ΔPRRA and WT competition assays based on percentage of total reads in that region (N=3). E) Quantitation by densitometry of the full-length spike (Black) and S1/S2 cleavage form (Gray) from distinct western blot experiments from Calu3 (n=2). F) Quantitation by densitometry of the full-length spike (Black) and S1/S2 cleavage form (Gray) from distinct western blot experiments from Vero E6 cell expressing TMPRSS2 (n=2). Data are presented as mean values.