title: A galactosidase immunosorbent test for carcinoembryonic antigen.
abstract: A galactosidase immunosorbent test for carcinoembryonic antigen (CEA) is described in which the amount of galactosidase adsorbed to a cellulose disc is a hyperbolic function of CEA concentration. Thus, molecules with CEA-like activity can be characterized by mathematical analysis of data obtained from the galactosidase immunosorbent test. By such analysis, CEA-reactive molecules in normal human plasma were distinguished from normal cross-reacting antigen and from authentic CEA. Variation of the amount of antibody-enzyme conjugate used in the galactosidase immunosorbent test permitted CEA-reactive material in plasma of a patient with rectal carcinoma to be antigenically distinguished from the CEA-reactive material in urine of a patient with bladder carcinoma. The galactosidase immunosorbent test is a useful tool for analysis of CEA-reactive molecules.
mesh_terms: D000042:Absorption; D000918:Antibody Specificity; D002272:Carcinoembryonic Antigen / Q000032:analysis*; D005696:Galactosidases; D006801:Humans; D007118:Immunoassay / Q000379:methods
chemical_list: D002272:Carcinoembryonic Antigen; D005696:Galactosidases