Application of immuno-blotting to the differentiation of specific antibodies in gonorrhoea.

The technique of immuno-blotting was used to examine the specificity of serum antibodies in patients with gonorrhoea and to define the significant antigenic determinant present in the desoxycholate extracts of gonococcal cell walls used previously for serological diagnosis. IgG but not IgA antibody was directed predominantly against lipopolysaccharide. Antibodies to outer membrane proteins were not found as frequently as expected. There was a suggestion from the results that antibodies to antigen PI was more common in systemic than in local infections.