Serum amylase determination by Somogyi's amyloclastic method with use of a photometric end-point.

Somogyi’s amyloclastic amylase assay has been modified by substitution of a spectrophotometric end point for visual observation, thereby increasing precision without changing the Somogyi assay units. A method of estimating starch concentration from the intensity of the starchiodine color reaction is described; absorbance is directly proportional to starch concentration. Somogyi’s finding that corn starch is the substrate showing least variation in ability to be degraded by amylase has been confirmed; a rapid method of standardizing the substrate is described. High amylase activities obtained using the amyloclastic method with sera containing lysed red cells are artifacts resulting from the interference of hemoglobin with the starch-iodine color reaction; the extent of the interference has been delineated, and means of avoiding it are described.