Inventors:
Mary E. Brown - Indianapolis IN
Lance S. Kuhn - Fishers IN
Robert J. McEnroe - Noblesville IN
Rebecca W. Muddiman - Indianapolis IN
Mary L. Ochs - Fishers IN
Assignee:
Boehringer Mannheim Corporation - Indianapolis IN
Boehringer Mannheim GmbH - Mannheim
International Classification:
G01N 33535
Abstract:
An immunoassay diagnostic kit, method, and apparatus for electrochemically determining the concentration of an analyte in a sample. A mixture is formed which includes the sample, an enzyme-acceptor polypeptide, an enzyme-donor polypeptide linked to an analyte analog (enzyme-donor polypeptide conjugate), a labeled substrate, and an antibody specific for the analyte to be measured. The analyte and the enzyme-donor polypeptide conjugate competitively bind to the antibody. When the enzyme-donor polypeptide conjugate is not bound to antibody, it will spontaneously combine with the enzyme acceptor polypeptide to form an active enzyme complex. The active enzyme hydrolyzes the labeled substrate, resulting in the generation of an electroactive label, which can then be oxidized at the surface of an electrode. A current resulting from the oxidation of the electroactive compound can be measured and correlated to the concentration of the analyte in the sample.