Effects of albumin and other proteins during assay of amylase activity

Addition of albumin, gamma-globulin, alpha-casein or submaxillary mucin to the assay system for chromogenic measurement of human or rat amylase with blue starch increased the amylase activity, albumin having the most effect. These proteins seemed to increase the activity by protecting amylase from inactivation. Amylase activity was higher in urine samples showing proteinuria than in urine samples without detectable protein. It is concluded that amylase assay is more reliable when a final concentration of albumin of 1 mg per ml is added at the dilution step and at the incubation step.