Production of carcinoembryonic antigen from a human colon adenocarcinoma cell line. II. Use of monoclonal antibodies to carcinoembryonic antigen for antigen purification and characterization.

Monoclonal antibodies (McAbs) were prepared against carcinoembryonic antigen (CEA), derived from human metastases to the liver of primary colon adenocarcinoma. A stable clone, secreting monoclonal anti-CEA antibody (Ab), was selected. The hybridoma cells were grown in BALB/C mice, forming ascites fluids containing 2-5 mg/ml of the relevant McAbs. Ascites fluids were purified using a DEAE-Sephacel column. The purified immunoglobulin fraction was characterized as IgG2b, having a dissociation constant of 2 X 10(-9)M. The potential use of these McAbs for CEA diagnosis and purification was evaluated: the IgG2b fraction, when bound to Sepharose 4B, facilitated the purification of CEA from spent media of a human colon adenocarcinoma cell line, resulting in iodination grade CEA; the anti-CEA McAbs demonstrated differential histochemical staining of various sections, both fresh and fixed; the McAbs were also found to be suitable as tagging Abs in a CEA RIA.