Fig. 5.

Virus yields in the presence or absence of rifampicin. (A) BS-C-1 cells were infected in triplicate with 3 PFU per cell of mutant or wild type VACV WR in the absence (Rif−) or presence (Rif+) of 100 μg of rifampicin per ml as described in the legend to Fig. 4. After 21 h, virus yields were determined by plaque assay in the absence of rifampicin. Standard error bars are shown. (B) Cells were infected in duplicate as described in panel A except that the multiplicity of infection was 0.33 PFU per cell and virus yields were determined at 0, 21 and 44 h. Abbreviations for mutant and wild type viruses are the same as in Fig. 4.