Isao Nishizono

Homogeneous enzyme immunoassay for macromolecular antigens using avidin biotin enzyme

A unique homogeneous enzyme immunoassay used for the determination of haptens and macromolecular antigens has been developed. It consists of avidin–antigen conjugate, anti‐ligand antibody, and biotin enzyme (propionyl‐CoA carboxylase). The immunological reaction of the conjugate with antibodies specific to ligand sterically prevents enzyme inactivation by avidin. Goat IgG and theophylline were used as model antigens. Avidin–theophylline conjugate inhibited 100% of enzyme activity. Avidin goat IgG conjugate inhibited 90% of enzyme activity.