Concurrent cytochemical localization of adenylate cyclase and peroxidase in the developing rat submandibular gland

An electron microscopic histochemical technique for the concurrent localization of adenylate cyclase and endogenous peroxidase is described. The procedure involves incubation of glutaraldehyde fixed tissue in adenylate cyclase medium followed by washing and incubation in 3,3'-diaminobenzidine tetrahydrochloride medium to demonstrate peroxidase activity. Adenylate cyclase was localized at the cell surface of the tissue investigated (20 day fetal rat submandibular gland) while peroxidase was localized in the rough endoplasmic reticulum and secretory granules of some cells. Biochemical and histochemical controls indicate that the procedure is valid. The potential use of this procedure and variations of the procedure are discussed.