Mycobacterium tuberculosis antigen 85 is a comple, Xenopus/Amphibian, of three related gene products of 30-31 kDa, Ag85A, B and C. All three proteins show fibronectin binding properties and act as mycolyltransferases involved in the final stages of mycobacterial cell wall assembly. This antibody is specific for Mycobacterium mycolyltransferas and reacts with M. tuberculosis Ag85C and M. smegmatis Ag85 homolog proteins. There is no crossreactivity with antigens from Listeria monocytogenes or Escherichia coli.