FIG. 1.

Expression and purification of IBDV VPX and VP3 in the baculovirus system. Crude extracts (CE) from cells infected with the corresponding recombinant baculovirus expressing VPX or VP3 and purified recombinant proteins (P) were electrophoresed in an SDS–11% polyacrylamide gel and stained with Coomassie blue (A) or transferred to nitrocellulose for immunoblotting (B). Proteins were incubated with a mixture of monospecific rabbit antisera against VPX/VP2 and VP3 and made to react with alkaline phosphatase-conjugated protein A. BGM70 cells infected with the SAL strain of IBDV (V) were included as a positive control. The numbers on the left indicate the molecular mass, in kilodaltons.