Ultrastructural localization of gold in macrophages and mast cells exposed to aurothioglucose

The ultrastructural localization of gold in resting, stimulated, and activated mouse peritoneal cells exposed in vivo and in vitro to aurothioglucose was examined by a photochemical technique. Activated macrophages from herpes simplex virus type 2 infected mice showed the heaviest accumulation of gold, located in phagolysosomes. Gold was also visualized in granules of mast cells and in nuclei of disintegrated cells. No gold was found in polymorphonuclear leucoctyes and in lymphocytes. The mechanism by which gold is taken up into the cells is discussed.