“…Nocardia and Mycobacterium have also been studied with serological methods such as agglutination, complement fixation, and sensitin tests as well as with immunodiffusion and immunoelectrophoresis. In these studies it has been shown that various species of Nocardia and Mycobacterium have antigens in common (1,3,7,10,11,13,14,26,27,42). Furthermore, with serological methods it has been possible to distinguish different species within the genus Nocardia (31, 32,41,46,51).…”