Rapid, reliable method for measuring serum lipase activity.

The method of Dirstine etal. [CLIN. CHEM. 14, 1097(1968)1has been modified to increase sensitivity and decrease manipulations. The modifications permit a 10-mm incubation, and a single analysis can be completed in 30 mm, or five concomitant assays can be done in an hour. Stability of the substrate has been increased by increasing the emulsifier concentration. Recovery of the fatty acid products has been improved by adding electrolyte to the copper reagent and by using combined organic solvents. Pancreatin was added to human serum to provide samples with increased activities, with behavior identical to that of pathological sera with increased lipase activities. Normal values for 100adults, 50 women and 50 men, ranged between 21 and 171 units, with a mean of 63 units. Within-day precision for 21 assays (mean activity, 641 units) was ±16 units (SD). Between-days pre. cision for 36 assays was ±18 units (SD), with a mean of 636units.