Analysis of HDL cholesterol

the enzymatic method Chod-PAP (reference 61 531, Bio-Mérieux S.A.), like the one described by Draeger et al. (1982), was used for the analysis of the cholesterol of lipoproteins of high density. The chylomicrons, VLDL (very low density lipoprotein) and LDL (low density lipoprotein) are precipitated by the

addition of phosphotungstic acid and of ion Mg++ to the sample. The concentration of HDL cholesterol (high density lipoprotein), which stays floating after centrifugation, is determined by an enzymatic way.

Analysis of LDL cholesterol

The analysis of the cholesterol of low density lipoprotein is determined by the precipitation method by heparin 100.000 UI/l) and of citrate sodium (0.064 mol/l), as stabilising agent (reference 14 992, diagnostica-Merck; Wieland et al., 1983). LDL was precipitated by heparin to their isoelectric point (pH 5.12). After centrifugation, HDL and VLDL stay floating and LDL were determined by enzymatic method.