This antibody labels the Epithelial Membrane Antigen (EMA) protein on the membrane and cytoplasm of the apical surface of secretory glandular epithelial cells in both normal and neoplastic tissue. It is a useful tool for identifying adenocarcinomas derived from secretory epithelia such as metastases of breast carcinoma. It is also a useful tool for identifying malignant mesothelioma, renal cell carcinomas, and meningiomas when used in a panel of antibodies.