FIG. 1.
Infectivity of wild-type and H230A viruses on BHK cells. BHK cells were electroporated with H230A-ic or wt-ic RNA, diluted 1:20 with nonelectroporated cells, and plated on duplicate coverslips. Cells were allowed to adhere for 2 h at 37°C, at which point half of the coverslips were switched to medium containing 20 mM NH4Cl to prevent secondary infection. After overnight incubation at either 37°C (A) or 28°C (B), cells were fixed with methanol and labeled with a rabbit polyclonal antibody against the SFV envelope glycoproteins, followed by fluorescein-conjugated goat anti-rabbit antibody. Samples were photographed by fluorescence microscopy, and data shown are a representative example of three experiments. Bar, 100 μm.