Improved method for determination of high density lipoprotein cholesterol using a sensitive reagent and a centrifugal...

Enzymic measurement of high density lipoprotein cholesterol (HDL-c) using a sensitive reagent and a centrifugal analyser is described. The Boehringer Mannheim cholesterol esterase/oxidase reagent has been modified by the inclusion of 2,4,6-tri-bromo-3-hydroxybenzoic acid (TBHBA) which reacts with hydrogen peroxide and the 4-aminophenazone/peroxidase system to produce a quinone-imine dye with a four-fold greater molar absorptivity than that produced with phenol. The resulting reagent system has been developed for use with a centrifugal analyzer for the determination of plasma HDL fractions isolated with polyethylene glycol 6000, for which a reagent of high sensitivity is required. The method is linear to 4 mmol/l of HDL-c and between-run and within-run CVs ranged from 1.01-2.54%. Reagent costs are currently $US 0.12 per test and large numbers of assay samples can be processed rapidly and conveniently. The mean (+/- SD) HDL-c value for men was 1.09 (+/- 0.33) and for women, 1.35 (+/- 0.37) mmol/l.