Mycobacteria cause diseases which occur the world over and which carry a considerable burden in morbidity, mortality and social problems. A battery of monoclonal antibodies specific for mycobacterial antigens would provide a useful tool for rapid diagnosis of mycobacterial diseases. Fourteen monoclonal antibodies to perchloric acid soluble antigen of M. tuberculosis were produced. Immunoglobulin isotypes of monoclonal antibodies were ten of immunoglobulin G2a, two of IgG3, and two of IgM. By means of Western blotting, monoclonal antibody detected the antigen of 54kD in TB-P. In the immunofluorescence assay, the monoclonal antibody showed a positive reaction with intact M. tuberculosis bacilli, M. tuberculosis in the pulmonary tissue of tuberculous patient and M. bovis BCG.