Direct enzymic measurement of glycerides in serum and in lipoprotein fractions.

A simple two-step procedure is now available for directly measuring triglycerides in whole serum and in lipoprotein fractions. I tested the performance of the assay, using pooled serum stored frozen, freshly prepared lipoprotein fractions, and pure glyceride standards. A parabolic concentration-response curve ensured linearity well beyond total glycerol concentrations of 10 mmol/L, but gave rise to misleading results for massively lipemic samples. Within-day CVs averaged 2.2% for the stored-frozen serum pools; mean day-to-day variation was 2.4%. Analytical recoveries of triglycerides, after lipoprotein fractionation, ranged between 101.9 and 103.7%. Aqueous glyceride standards gave results equivalent to between 95 and 105% of their glycerol content.