FIG. 3.

UV-C irradiation of Vero cells prior to infection enhances the plating efficiencies of ICP0⁻ viruses. Twenty-four-hour-old Vero cell monolayers in six-well plates (35-mm diameter wells) were subjected to 0, 1, 2, 3, 4, or 6 mJ/cm² of UV-C irradiation. Monolayers at the 0-h time point were infected immediately. All others were incubated at 37°C until the time of infection as indicated on the x axis. Replicate monolayers were infected with 100 PFU/well of wild-type (KOS) or ICP0⁻ virus (7134 or n212). (A, C, and E) Plaques were counted, and (B, D, and F) plaque numbers were divided by the number of plaques on mock-irradiated monolayers to determine the change (n-fold) in plating efficiency. The average number of plaques/well is shown, and error bars indicate the standard deviations of two independent measurements.