Reference interval for serum alpha-amylase determined with p-nitrophenyl-alpha-D-maltoheptaoside as a substrate.

The reference interval for the catalytic concentration of alpha-amylase (EC 3.2.1.1) in serum was determined in 326 blood donors. The analytic method used p-nitrophenyl-alpha-D-maltoheptaoside as substrate, which allows a continuous colorimetric measurement at 37 degrees C of the catalytic concentration of alpha-amylase in serum. The limits obtained were 0.7-3.8 mukat/l (42-228 U/l), which were in agreement with the only previous report found.