GEL‐DIFFUSION METHOD FOR THE ASSAY OF α‐AMYLASE

Abstract

α‐Amylase can be readily estimated by allowing a solution of the enzyme to diffuse from a filter paper disc into an agar gel containing starch or β‐limit dextrin. The starch is degraded in the zones into which the enzyme penetrates so that, when the gel‐surface is flooded with a solution of iodine, circular clear zones are obtained against the starch‐ or dextrin‐iodine background colour. When other conditions are constant, the diameter of the clear zone is proportional to the logarithm of enzyme concentration. 1962 The Institute of Brewing & Distilling