Immunofluorescent labeling of human salivary glands was carried out with a battery of monoclonal antibodies reactive with specific cytokeratin polypeptides. All the epithelial elements of the glands were positively labelled by a broad-spectrum cytokeratin antibody (KG 8.13) and by antibody Ks 18.18, which reacts with cytokeratin No. 18 exclusively. Labelling of frozen sections with antibody KM 4.62, which is reactive with the 40 Kd (No. 19) cytokeratin, was confined to the ductal system and apparently absent from the acini. Antibody KA-1, reactive with polypeptides 4, 5 and 6 stained both the myoepithelial cells and the basal cells of the large ducts. Antibody KS 8.58, however, reacted with the basal cells exclusively. It is thus proposed that the combined use of the various monoclonal antibodies may provide a most useful probe in studies on epithelial cell diversity in normal salivary glands as well as in pathological disorders of that gland.
