Automated procedure for kinetic measurement of total triglycerides (as glycerol) in serum with the Gilford System 3500.

An automated procedure is used on the Gilford 3500 Computer-Directed Analyzer to measure serum triglycerides indirectly by using aqueous glycerol standards. Most enzymatic methods require long hydrolysis or awkward saponification. The method of Bucolo and David [clin. Chem. 19, 476 (1973)], in which lipase and glycerol kinase are used, is modified. The kinetic procedure described eliminates the need for a serum blank. It uses "Eskalab" bulk reagents and reduces both time and cost per test by measuring the decreasing NADH concentration from the glycerol kinase reaction at 340 nm after enzymatic hydrolysis at room temperature. The change in absorbance of the standard during a 14-s measuring time is used in the ratiometric calculation of the unknowns. The use of a stable aqueous standard that can be reliably and accurately prepared makes this method ideal for the traceability desired by many organizations. Reagent blank drift did not affect the results. A correlation coefficient of 0.991 for comparison with the manual endpoint method and a typical CV of 2.25% show this method to be accurate and reliable.