Evaluation of precipitation and direct methods for HDL-cholesterol assay by HPLC.
HDL-cholesterol (HDL-C) values measured by precipitation (sodium phosphotungstate-MgCl2) and direct methods were compared with those obtained by HPLC with a new column (TSKgel Lipopropak) and an eluent (TSKeluent LP-1). The HDL-C values determined by the precipitation method were significantly (P <0.001) lower than those by the HPLC method, whereas the HDL-C values by the direct method were slightly but significantly higher (P <0.02) than those by the HPLC method. A quantitative HPLC analysis of the cholesterol concentration in HDL and non-HDL fractions in the supernatant of serum separated by precipitation reagents with different MgCl2 concentrations ranging from 7.3 to 44 mmol/L revealed that reagents with >22 mmol/L MgCl2 precipitated part of HDL as well as non-HDL lipoproteins. The HPLC method providing quantitative and qualitative information with high precision was regarded as being a reliable approach for HDL-C assay. The HPLC can be also used to evaluate alternative methods for cholesterol assay.
Okazaki
M
M
Laboratory of Chemistry, College of Liberal Arts and Sciences, Tokyo Medical and Dental University, Chiba, Japan. okazaki.cul@cul.tmd.ac.jp
Sasamoto
K
K
Muramatsu
T
T
Hosaki
S
S
D011232:Chemical Precipitation; D008076:Cholesterol, HDL / Q000097:blood*; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D006801:Humans; D015636:Magnesium Chloride / Q000737:chemistry
D008076:Cholesterol, HDL; D015636:Magnesium Chloride