Pancreatic amylase is a digestive enzyme secreted by the pancreas. It consists of a single polypeptide chain with a molecular weight of 54 kDa. Pancreatic amylase occurs in serum at a concentration of about 60µg/L, from a total amylase concentration in serum of about 120µg/L. Pancreatic amylase and salivary amylase are the products of separate genes and, although they share 98% amino acid sequence homology, they differ in molecular size, isoelectric point and antigenic properties. Measurement of amylase concentrations in serum is a diagnostic test for various pancreatic disorders (especially acute and relapsing pancreatitis).