The use of density gradient centrifugation for the separation of serum lipoproteins

Flotation through NaBr density gradients is shown to be a convenient method for the analysis of hyperlipoproteinaemic sera in cases where gel electrophoresis gives ambiguous results. It is also demonstrated that flotation through density gradients provides a rapid method for preparing small samples of pure very low density lipoprotein (VLDL) and low-density lipoprotein (LDL). These classes of lipoprotein can be separated simultaneously from up to 2 ml of serum with a centrifugation time of only 2 h. The fractions so prepared are shown to be comparable with fractions separated by stepwise flotation.