Assessment of Dharmendra antigen. III. Comparative study with Mitsuda antigen

Four fractions each from Dharmendra and Mitsuda antigen have been obtained by step-wise centrifugation and sonication of the antigen. These fractions have been assessed for their capacity of inducing skin delayed hypersensitivity response. While, it has been noted that all fractions of both types of antigens can induce a good early reaction, the late skin reaction is only mounted by intact bacilli of both types of antigen. When compared at a constant bacillary concentration, Dharmendra antigen has produced better early skin reaction than Mitsuda antigen, whereas the intensity of late skin reaction is almost equal with both the antigens. The hypothesis has been put forward that the early, as well as the late reaction are produced by the same antigen and this antigen is located in the protoplasm of M. leprae.