Differences in the purification effect of carcinoembryonic antigen (CEA) from the three different hepatic metastases...

Carcinoembryonic actigen (CEA) was purified from three liver metastases of carcinoma recti by a conventional procedure involving perchloric acid extraction of tumor tissue and fractionation of the extract by gel filtrations on Sepharose 4B and Sephadex G-200. The preparations obtained showed a different degree of heterogeneity in SDS-polyacrylamide gel electrophoresis and crossed immunoelectrophoresis, and also a different antigenic activity. One of preparations obtained was a homogeneous CEA by all these criteria, and two others showed heterogeneity and lower antigenic activity. The most heterogeneous CEA preparation was further purified by the affinity chromatography on Concanavalin A-Sepharose 4B and by DEAE-Sephadex A-50 chromatography and the usefulness of these procedures for purification of CEA is compared.