Immunoblot analysis of isogenic strains. Immunoblot analysis of Vir protein profiles of various strains using antibodies against VirB1, VirB9, VirB10, VirB11, and VirE2. Protein samples from various strains were run on a 10% (w/v) denaturing polyacrylamide gel, and the ECL Plus western blotting and detection system from Amersham-Pharmacia Biotech was used for analysis.