A comparison of the physicochemical properties of carcinoembryonic antigen in extracts of tumour tissue, ascitic and cyst fluid from ovarian cancer.

In view of the reported disagreement in the physicochemical properties of ovarian carcinoembryonic antigen (CEA), this study was undertaken to compare the properties of CEA obtained from extracts of ovarian tumour tissue, ascitic fluid and cyst fluid. On the basis of molecular weight estimation and binding properties with Concanavalin A and wheat germ lectin, ovarian CEA from these three sources appeared similar, and also possessed similar properties to those of colonic CEA. On isoelectric focusing, however, it was found that the isoelectric point of CEA from tumour tissue and cyst fluid differed from that from ascitic fluid. It is most likely that this is due to a loss of sialic acid from the CEA released into ascitic fluid.