Mycobacteriumtuberculosis (MTB) is a pathogenic bacterial species in the genusMycobacterium and the causative agent of most cases of tuberculosis. Firstdiscovered in 1882 by Robert Koch, M. tuberculosis has an unusual, waxycoating on the cell surface (primarily mycolic acid), which makes the cellsimpervious to Gram staining so acid-fast detection techniques are usedinstead. The physiology of M. tuberculosis is highly aerobic and requireshigh levels of oxygen. Primarily a pathogen of the mammalian respiratorysystem, MTB infects the lungs. The most frequently used diagnostic methodsfor TB are the tuberculin skin test, acid-fast stain, and chest radiographs. Suitable for use inELISA and Western blot. Each laboratory should determine an optimum workingtiter for use in its particular application. Other applications have not beentested but use in such assays should not necessarily be excluded.