Characterization and comparison of mycobacterial antigens by discontinuous pore gradient gel electrophoresis

Concentrated culture filtrates and cell extracts were prepared from selected mycobacteria and analyzed by a multistage polyacrylamide electrophoretic procedure. Various staining procedures were used to detect protein, carbohydrate, nucleic acid, and lipid constituents. Visual examination of the more prominently stained components indicated differences and similarities in each species of Mycobacteria. The majority of the individual components were of small molecular weight; however, there appeared in all culture filtrates and extracts examined a slowly moving protein component of relatively large molecular size. Evidence based on immunodiffusion suggests that it is a common mycobacterial antigen.