title: Heparin--Mn2+ quantitation of high-density-lipoprotein cholesterol: an ultrafiltration procedure for lipemic samples.
abstract: We describe a modified heparin--Mn2+ procedure for high-density-lipoprotein cholesterol quantitation, especially in lipemic samples. High-density-lipoproteins may be estimated as cholesterol remaining in plasma supernates after precipitation of other lipoproteins by heparin and Mn2+ treatment. However, in lipemic samples or those from non-fasting individuals, the lower density of the precipitated chylomicrons, very-low-, and low-density-lipoproteins frequently prevents their sedimentation by the usual low-speed centrifugation, and high-density-lipoprotein cholesterol thus is overestimated in the resulting turbid supernates. Sedimentation is improved by a twofold increase in Mn2+ concentration to 92 mmol/liter. The procedure reported here produced clear supernates in more than 95% of samples tested. Any remaining turbid supernates can be cleared by a simple, convenient ultrafiltration technique. The filtration removed essentially all of the very-low- and low-density-lipoproteins without removing appreciable amounts of high-density-lipoproteins.
mesh_terms: D001053:Apolipoproteins / Q000097:blood; D002784:Cholesterol / Q000032:analysis*; D006493:Heparin; D006801:Humans; D006949:Hyperlipidemias / Q000097:blood*; D008075:Lipoproteins, HDL / Q000097:blood; D008345:Manganese; D014280:Triglycerides / Q000032:analysis; D014461:Ultracentrifugation / Q000379:methods; D014462:Ultrafiltration / Q000379:methods
chemical_list: D001053:Apolipoproteins; D008075:Lipoproteins, HDL; D014280:Triglycerides; D008345:Manganese; D006493:Heparin; D002784:Cholesterol