The monolayer and organ culture of human colorectal carcinomata and the associated "normal" colonic mucosa and their production of carcinoembryonic antigens.

The carcinoembryonic antigen (CEA) was produced and released by human colorectal carcinomata and also the normal attached mucosa when maintained in both monolayer and organ culture. Immunoperoxidase cytochemical methods were employed for the cellular localization of CEA which was demonstrable only on the neoplastic cells. Gel filtration and immunological methods confirmed that CEA, produced by normal and neoplastic cells, had properties similar to "authentic" CEA derived from metastatic colorectal carcinomata. In addition, two other CEA cross-reacting macromolecules, neither of which was CCEA-2, were produced by these tumours in culture.