FIG. 5.
Single-step growth analyses of the WT, UL49−, and UL49R viruses. Vero cell monolayers were infected with the WT, UL49−, and UL49R viruses at an MOI of 5 PFU/cell for 1 h to allow virus adsorption. The cells were then washed extensively with citrate buffer to neutralize and remove unbound virus. The cells were overlaid with medium and held at 37°C. At the indicated times postinfection, the infected cells (A) and the overlaying medium (B) were analyzed separately by plaque assay to determine intracellular and extracellular viral yields, respectively.