Patent ID: 7001737

Claim:
An assay for trypsin inhibitors in urine which comprises (a) contacting a urine test sample with a buffered assay medium comprising (i) trypsin in an amount of from 10 to 750 IU/mL, (ii) a substrate for trypsin which will produce a detectable response when cleaved by trypsin present in a concentration of from 0.2 to 50 mM and (iii) a polycarboxylic chelating agent present in an amount of from 0.2 to 50 mM, and (b) correlating the concentration of trypsin inhibitor with the detectable response from the cleaving of the substrate, wherein the polycarboxylic chelating agent reduces variation in detected amounts of trypsin inhibitor caused by the presence of calcium ions in the urine in reference to a control sample lacking the polycarboxylic chelating agent.