ANTIGENS OF MYCOBACTERIUM TUBERCULOSIS

Abstract

Crude antigens were obtained from disrupted M. tuberculosis, strain H37Ra, and the Sauton medium on which it was grown. Cytoplasm from the disrupted cells and concentrated culture filtrate were fractionated by stepwise precipitation with ammonium sulfate at 30, 50, 70, and 100% saturation. The ammonium sulfate precipitate fractions were further fractionated by chromatography on DEAE cellulose. The eluent was monitored for protein and the eluent fractions were then pooled according to protein peaks. All fractions were tested in gel double diffusion and immunoelectrophoresis against mycobacterial antisera. Ammonium sulfate precipitation did not effect complete separation of the protein antigens. Column chromatography separated the antigens further, but only a few fractions from the column contained a single protein band. Antigens from filtrate and cytoplasm were compared by gel diffusion and immunoelectrophoresis; all precipitating antigens of the culture filtrate were also found in the bacterial cytoplasm.