THE DISTRIBUTION AND CHEMICAL COMPOSITION OF ULTRACENTRIFUGALLY SEPARATED LIPOPROTEINS IN HUMAN SERUM

In the past few years several methods have been developed for the analysis of serum lipoproteins. Lindgren, Elliott, and Gofman (1) have utilized the relatively low density of the lipoproteins to separate them from the other serum proteins by ultracentrifugal flotation. Quantitation was sub- sequently performed by refractometric methods in the analytical ultracentrifuge. Separations of lipoproteins have also been made by Cohn frac- tionation in cold ethanol, and the quantities of lipoprotein have been estimated from the lipid. content of the fractions (2, 3). Widely used at the present time is the method of zone electrophoresis with quantitation either by staining (4) or by chemical analysis of eluates from the support- ing medium (5, 6).