Precipitation of plasma lipoproteins by PEG-6000 and its evaluation with electrophoresis and ultracentrifugation.

A neutral polymer precipitation procedure for fractionation of human plasma lipoproteins is described. The method was also tested preliminarily for fractionation of rat plasma lipoproteins. Polyethylene glycol-6000 (PEG-6000) at a concentration of about 12% and at pH 7.9 precipitated human plasma very low density (VLDL) and low-density (LDL) lipoproteins completely. Precipitation was independent of time and temperature. VLDL and LDL could not be precipitated separately. Polyethylene glycol-6000 precipitation can be used for rapid determination of high-density (HDL) lipids and of the ratio of HDL to LDL lipids.