FIG. 3.

Virus entry of wild-type (WT), pp28STOP61, and pp28STOP50 viruses in HF. Monolayers of HF on 13-mm coverslips were infected at 4°C with wild-type, pp28STOP61, and pp28STOP50 viruses at an MOI of approximately 5. Following an incubation at 4°C for 90 min, the cultures were shifted to 37°C for 2 h. Coverslips were fixed at 0 min and 2 h, and then the cells were assayed for expression of IE-1 antigen by using MAb p63-27 developed with a Texas Red-conjugated anti-mouse immunoglobulin G (red). Nuclei were stained with Hoechst dye (blue).