Abstract: A method is described for measuring the amount of analyte present in a sample containing the analyte using a homogeneous amperometric immunoassay. The analyte is chemically bonded to a suitable carrier molecule, which is also chemically bonded to an electroactive molecule. The electroactive molecule, such as ferrocene carboxylic acid, contains a redox center which is capable of transferring a charge to an electrode. A preferred carrier molecule is bovine serum albumin (BSA), while suitable analytes include digoxin, theophylline and HCG. The immunoassay is conveniently performed by applying a voltage to a set of electrodes.

Abstract: A method is described for measuring the amount of analyte present in a sample containing the analyte using a homogeneous amperometric immunoassay. The analyte is covalently bonded to a suitable carrier molecule, which is also covalently bonded to an electroactive molecule. The electroactive molecule, such as ferrocene carboxylic acid, contains a redox center which is capable of transferring a charge to an electrode. A preferred carrier molecule is bovine serum albumin (BSA), while suitable analytes include digoxin, theophylline and HCG. The immunoassay is conveniently performed by applying a voltage to a set of electrodes.

Abstract: A substantially pure antigen found on normal and benign breast epithelial cell membranes and in breast cancer cells, fused cell hybrids which produce antibodies specific for such antigen, the monoclonal antibodies produced by such fused cell hybrids, a method for detecting the presence of breast cancer in a patient which is based on measuring the concentrations of one or more determinants of such antigen in a patient sample, and a method for either identifying those breast cancer patients whose tumors would respond to estrogen manipulation or determining prognosis based on the degree of differentiation, which method is based on measuring the concentration of an estrogen-modulated determinant of such antigen.