The participation of common and species-"specific" antigens of Mycobacteria in the tuberculin skin reaction.

Protoplasmic extracts isolated from four different species of mycobacteria contained common and species-specific antigens. Both the common and the specific antigens were involved in the elicitation of the tuberculin reaction in sensitized guinea pigs. The elimination of the common antigens from the extracts by means of cross absorption with heterologous mycobacterial antibodies led to preparations which, at the doses used in this study, elicited a cutaneous reaction in animals sensitized with the corresponding strains only. Moreover, the tuberculin activity of the common antigens was about the same in animals sensitized either with homologous or heterologous strains.