Particle (genome)/PFU ratios of vA8myx and mutants. (A) BS-C-1 cells were infected in duplicate with 5 PFU/cell of vA8myx, vA8myxΔA26, vA8myxΔG6, or vA8myxΔA26ΔG6 or the WT virus. After 24 h, the cells were harvested and lysates prepared. Samples of the lysates were used to determine PFU levels in BS-C-1 cells, and additional samples were treated with Benzonase. Resistant DNA was quantified by ddPCR using VACV-specific primers. (B) BS-C-1 cells were infected with vA8myxΔG6rev, vA8myxΔG6, vA8myxG6R(C108S), vA8myxG6stop, or the WT virus as described for panel A. PFU and DNA levels were determined as described for panel A.