抄録
An inverse relationship has been demonstrated between plasma high-density lipoprotein (HDL) cholesterol level and the incidence of coronary heart disease. Therefore, measurement of HDL cholesterol is of great importance.
In the present study we compared three different methods for the estimation of HDL cholesterol in plasma samples.
The methods were as follows.
(1) Ultracentrifugation.
Cholesterol was determined in the d<1.063g/ml fraction from 2ml of plasma after centrifugation at 100, 000 G for 20hr.
(2) Heparin-Mn2+ precipitation.
To 2ml of plasma we added 80μl of a heparin solution (5, 000units/ml) and 100μl of MnCl2 solution (1 Mol/l), and immediately mixed. After the sample had stood for 30min. in an ice bath, the sample was centrifuged (1, 500G, 30min., 4°C) and cholesterol was determined in the supernate.
(3) Sodium phosphotungstate-Mg2+ precipitation.
To 2ml of plasma we added 200μl of a sodium phosphotungstate solution and 50μl of MgCl2 solution (2 Mol/l). After mixing in a vortex mixer, the sample was centrifuged (1500G, 30min., 4°C) and cholesterol was determined in the supernate.
HDL cholesterol levels of 138 subjects were measured by two precipitation methods and for 32 of them the three methods were used simultaneously.
The correlation coefficients were 0.939 between ultracentrifugation and heparin-Mn2+ precipitation methods, 0.919 between ultracentrifugation and phosphotungstate-Mg2+ methods, and 0.966 between the two precipitation methods.
Our results showed similar results for the cholesterol content of HDL determined by the three methods.
Both precipitation methods are simple and appropriate for routine clinical laboratory use.
