Preparation of type-specific anti-M streptococcal sera by ummunization with acid-hydrolyzed cells

The present study describes a method which simplifies the preparation of type-specific anti-M streptococcal sera. The procedure is based on vaccination with acid-hydrolyzed cells. The method makes possible the preparation of antisera from M strains which are problematic by conventional vaccination and is very useful for preparing all anti-M sera. The antisera obtained by the above method are devoid or almost devoid of cross-reactive antibodies.