FIG. 6.

PEG-induced infectivity of PrV on MDBK and NB cells. MDBK (white bars) and NB cells (black bars) were infected with serial dilutions of PrV-1112, PrV-gC⁻, PrV gD⁻ Pass, and PrV gCD⁻ Pass. After X-Gal staining, infectious titers were determined by counting either plaques (for PrV-1112 and PrV-gC⁻ on both cell lines and for PrV gD⁻ Pass and PrV gCD⁻ Pass on MDBK cells) or single infected cells (for PrV gD⁻ Pass and PrV gCD⁻ Pass on NB cells). Relative infectivities and standard variations (error bars) compared to control plates which were not treated with PEG are indicated.