A recombinant human EpCAM fragment from extracellular domain (within amino acids 100-224) was used as the immunogen for the EpCAM antibody.
EGP40, which is a 40-43kDa transmembrane epithelial glycoprotein, is also identified as epithelial specific antigen (ESA), or epithelial cellular adhesion molecule (Ep-CAM). It is expressed on baso-lateral cell surface in most simple epithelia and a vast majority of carcinomas. Antibody to Ep-CAM has been used to distinguish adenocarcinoma from pleural mesothelioma and hepatocellular carcinoma. This antibody is also useful in distinguishing serous carcinomas of the ovary from mesothelioma.