Purification and Characterization of Three Immunodominant Proteins (38, 30, and 16 kDa) of Mycobacterium tuberculosis

Specific mycobacterial antigens are an important prerequisite in the serodiagnosis of tuberculosis. Many studies have reported the use of both native and recombinant proteins. Even though recombinant proteins can form standardized reagents with unlimited supply, their diagnostic test characteristics were not satisfactory in some cases. In this study we have purified the 38-, 30- (antigen 85B), and 16-kDa native antigens of Mycobacterium tuberculosis by procedures with limited number of steps. Starting with the secreted antigens of M. tuberculosis H37Rv, the 38-kDa form was purified by preparative isoelectric focusing, followed by preparative electrophoresis