Hyperimmune sera raised against SV bacterial fusion proteins recognized baculovirus-expressed SV capsid proteins in a type-specific manner. Western blot immunostained with (A) guinea pig anti-GST-Mex340 hyperimmune serum (1:5,000) and (B) guinea pig anti-GST-Mex14917 hyperimmune serum (1:5,000). Lane 1, wild-type baculovirus; lane 2, baculovirus-expressed recombinant Mex340; lane 3, baculovirus-expressed recombinant Mex14917; lane 4, MBP-Mex340 fusion protein. MW, molecular weight marker (molecular weights in thousands). For lanes 1 to 3, sucrose gradient fraction 6-containing recombinant VLPs were used.