Determination of α-amylase activity: Methods comparison and commutability study of several control materials

Abstract

Six different methods for α-amylase determination were compared by assaying human serum samples covering a wide range of α-amylase values. All the methods studied use as substrate a maltooligosaccharide with a chromophore group at the reducing end; some are chemically blocked at the nonreducing end. Intermethod comparison by regression and correspondence analyses showed significant differences for two methods. The commutability of 12 commercial control materials containing α-amylase was also assessed by the different methods in comparison with human serum specimens containing the pancreatic and salivary isoenzymes. We also studied the behavior of pancreatic and salivary materials prepared in our laboratory. Control materials with α-amylase of nonhuman origin were not commutable with the enzyme in human sera and should not be used for intermethod calibration.