The cell-surface antigens of Bacteroides vulgatus.

The cell surface of Bacteroides vulgatus was examined by electron microscopy. The outer membrane complex was removed by EDTA and mild sonication and the antigens of this complex were characterized by enzyme-linked immunosorbent assay and crossed immunoelectrophoresis. The species-specific antigen was identified and was shown to be the major outer membrane protein with a molecular weight of 100 000.