Analysis of the soluble cytoplasmic components of mycobacteria and nocardia by crossed immunoelectrofocusing

Soluble cytoplasmic components of Mycobacterium tuberculosis, strains H 37 Ra, and Washington II, Mycobacterium bovis, strain BCG and Nocardia asteroides were analysed by isoelectric focusing, crossed immunoelectrophoresis, and crossed immunoelectrofocusing. Using con A-affinity chromatography con A-reactive polysaccharides could be separated from the cytoplasmic fraction which improved the focusing effect. The isoelectric focusing patterns of the various mycobacterial strains were similar, however, concentration differences of the respective components might occur. N. asteroides had a different pattern. By crossed immunoelectrofocusing it was shown that most of the bands of the focusing pattern had antigenic character. Con A-reactive polysaccharides were located near to the cathode, and the con A-nonbound antigens occured close to the anode. Cross-reaction between mycobacteria and N. asteroides was remarkable. In crossed-line immunoelectrophoresis four lines of N. asteroides antigens were identical with the highest peaks of M. bovis, strain BCG antigens.