Monoclonal antibody-based immunoassay for carcinoembryonic antigen (CEA) measurement in human serum

Clinical oncology requires methods to detect tumor markers in patients sera and tissues Presently, monoclonal antibodies (MAbs based enzyme immunoassays are amongst the most advantageous techniques. Here we present a sensitive and specific double-antibody enzyme immunoassay for serum me surement of carcinoembryonic antigen (CEA). It has been developed with MAbs which recognize nonoverlapping peptide epitopes on the antigen molecule. The capture MAb 6C7 is GOLD 1 highly specific antibody while the tracer MAb 5.D11, labeled with biotin, is GOLD 4 that cross-reacts with nonspecific cross-reacting antigen (NCA) expressed on granulocytes. In addition the biotinylate MAb is shown to be also useful to detect CEA by immunohistochemistry.