SIGNAL ENHANCEMENT IN MAGNETIC IMMUNOASSAY BY INHIBITION OF ENZYMATIC CATALYSIS

摘要

A method for enzyme immunoassay for a ligand suspected to be present in a liquid sample includes signal amplification by use of at least two enzymes and a blocked inhibitor for one of the enzymes. Ligand present in the liquid binds to an antiligand conjugated to a magnetic particle and an enzyme-labeled tracer. After binding, the particles are separated magnetically and the enzyme in the tracer removes the blocking group from the blocked inhibitor. The inhibitor inhibits a second enzyme which catalyzes the conversion of a substrate to a product. The presence or absence of the ligand in the liquid is indicated by a signal, such as a color change or a rate of color change. The invention includes a kit of materials useful for performing the method of the invention.