Immunologic evidence that staphylococcal alpha toxin is oriented on membranes.

Antibodies to staphylococcal alpha toxin were separated into two distinct populations. One population prevented binding of alpha toxin onto erythrocyte membranes. The other population neutralized after the toxin was bound onto erythrocytes and thereby brought about an indirect hemagglutination reaction. The data suggest that alpha toxin has a membrane-binding region.