Patent ID: 6936429

Claim:
An assay for the presence or amount of an analyte in a sample comprising a) combining in solution the sample to be assayed for the presence or amount of analyte; a ligand that binds the analyte in solution; a first substrate, a second substrate, and a scavenger compound; wherein the analyte has a first enzymatic activity that acts on said first substrate to produce a colorless first product; the ligand is directly or indirectly bound to an enzyme with a second enzymatic activity that acts on the second substrate to produce a colorless second product; the scavenger compound is a scavenger for the first product or the second product; the first product and the second product chemically combine to produce a colored reaction product; and, the first enzymatic activity is a hydrolase activity or an oxidase activity and the second enzymatic activity is a hydrolase activity if the first enzymatic activity is an oxidase activity and is an oxidase activity if the first enzymatic activity is a hydrolase activity; b) detecting the production of the colored reaction product; and c) relating the production of the colored reaction product with the presence or amount of analyte in the solution.