Development of a new method for determination of α -amylase activity based on rate of NADH increase

A new method was developed stoichiometrically to determine the activity of a amylase. It was tested by allowing a single attack of a -amylase on a substrate. During the process, the NADH level changed. Isopropylidene fructosyl maltoheptaoside was used as the substrate while glucoamylase, sucrose phosphorylase, phosphoglucomutase, and glucose-6-phosphate dehydrogenase were used as the coupling enzymes. By measuring the rate of NADH production during the test, the activity of a -amylase could be determined. This method sustained less interference from various substances, that are found in the specimen. It can also be applied easily to various analytic devices. Furthermore, the reagents used in this method are highly stable. Therefore, relatively consistent and precise results can be obtained, which agree well with those of other methods. In conclusion, this method is thought to be suitable for use in routine tests.