Demonstration of Carcinoembryonic Antigens (Cea), Nonspecific Cross‐reacting Antigens (Nca) and an Associated Alpha Protein in Normal Human Tissues and Fluids by Immunodiffusion Techniques

Perchloric acid extracts (PCA) of cancer tissues, normal and inflammatory tissues, normal sera, urines and salivas were studied to detect carcinoembryonic antigens (CEA) and cross‐reacting antigens. The extracts were tested in high concentration by immunodiffusion methods in agarose gel. Substances which showed complete identity with CEA were found in apparently normal tissue, saliva and urine and in inflammatory tissue as well as in primary lung cancer. In addition, material which cross‐reacted with CEA was found in all the samples tested in adequate concentrations, including serum, saliva and urine. Both CEA and the non‐specific cross‐reacting antigens (NCA) were found in samples of purified blood group substance A and B and in saliva from secretor and non‐secretor. An α‐protein was found in PCA extracts of normal and cancer tissue, normal serum and some urines. Some preliminary observations are reported on the α‐protein which seems to share antigenic determinants with the βE‐protein possessing NCA determinants.