Evaluation of a new inhibitor test for isoamylase on Hitachi 705 analyser

We describe a simple and rapid method for measuring pancreatic and salivary type amylases using the Hitachi 705 analyser. The determination is based on the inhibition of salivary amylase using an inhibitor isolated from wheat germ. The precision of the proposed method was very good: within-day precision varied from 0.4 to 2.5% (CV) and day-to-day precision from 2.2 to 3.7% (CV). The new application correlated well with another commercially available inhibition method. As the standardization is very stable and the assay procedure exactly the same as for the total amylase assay, the proposed method is suitable for routine isoamylase determination. Reference values for pancreatic and salivary amylase activities are presented.