Ultrastructural localization of carcino-embryonic antigen in a continuous human tumour cell line (LS 174 T) in relation to morphometric investigations.

The synthesis of carcinoembryonic antigen (CEA) in human tumour cell cultures has been investigated at the ultrastructural level in the colon carcinoma cell line LS 174 T. By application of a CEA-specific antibody fraction, gained from goat serum which was directly coupled with horse radish peroxidase (HRP), the expression of CEA could be followed in the cell culture both intra- and extracellularly with ultra-immunohistochemical methods, utilizing the pre-embedding technique. Morphometric and ultra-immunohistochemical investigations showed the possible involvement of the Golgi systems in CEA production. The changes in the volume fraction of the Golgi apparatus related to the total cell volume showed a direct correlation with the CEA content in the cell culture supernatants. Freeze-etch control experiments revealed negligible structural changes in the cells following ethyl-dimethyl-aminopropylcarbodiimide (EDC)-and saponin permeation techniques.