Multienzyme assay Incubate sample with a mixture of peptidase, trypsin and chymotrypsin and monitor pH change over time.

• Liberated carboxyl groups release hydrogen ions resulting in a pH drop 复合酶法-将样品与肽酶，胰蛋白酶，胰凝乳蛋白酶共同培养 ，观察pH值随时间的变化。游离的羧基基团释放氢离子，导致pH下降。