Sepcific tubercle antigen.

Identification and isolation of the specific antigen of M. tuberculosis with the aid of an antiserum against the antigen antibody complex prepared by Goudie's method from the serum of tberculous patients is described. The position of the specific antigen on the disc electrophoresis column comprising four protein bands has been identified and separated. The antibody has been identified as IGg. More sophisticated techniques should enable the isolation of the specific antigen in practical amounts. The availability of such an antigen should greatly advance the serological diagnosis of tuberculosis.