FIG. 7.

Virions produced upon infection with recombinant viruses. MDBK cells were infected with recombinant viruses at an MOI of 2.0 PFU/cell. Infected cells were metabolically labeled with ³⁵S-amino acids, and 5 h later, cell and medium fractions were harvested. Viral proteins from cell lysates were collected by immunoprecipitation. Virions from culture supernatants were purified by centrifugation through sucrose cushions followed by flotation on sucrose gradients and then loaded directly onto SDS gels. Viral proteins were separated by SDS-PAGE and visualized using a phosphorimager. The data shown are representative of two independent experiments.