Rapid laser nephelometric determination of amylase activity in serum and urine.

We describe herein a rapid and sensitive laser nephelometric method for the determination of serum and urinary amylase activities. Our data showed that the change in relative light scattering (RLS) of an amylopectin substrate measured by a laser nephelometer related directly with amylolytic activity of amylase from 50 to 600 IU/L. Within-run variations at 293 and 769 IU/L sera showed CV's of 5.0% and 3.1%, respectively. Day-to-day variation for the same sera showed CV's of 7.2% and 4.7%, respectively. Correlation studies using the manual Phadebas dye-starch complex method and with the Roche amylochrome method showed correlation coefficients of 0.99 and 0.95, respectively. Using urine specimens, the correlation studies also showed a correlation coefficient of 0.98. These studies indicated that the proposed method was sensitive, fast, economical and easily adaptable to emergency and routine applications.