A monoclonal antibody (ML30) recognizing the 65-kDa heat-shock protein
of mycobacteria and reacting with homologous human protein was found
to stain various porcine tissues. Development of this reactivity was s
tudied. The first ML30-positive cells were embryonic hepatocytes. The
protein reacting with the ML30 antibody was localized predominantly in
the Golgi area and mitochondria of hepatocytes. Cell membranes of som
e peripheral blood lymphocytes were also found to bind ML30.