The separation of plasma lipoproteins using gel electrofocusing and polyacrylamide gradient gel electrophoresis

Polyacrylamide gel electrofocusing and gradient electrophoresis have been used to separate the lipoproteins in whole plasma and in fractions prepared by sequential flotation in the ultracentrifuge and by precipitation with dextran sulphate and manganous chloride. After the two-dimensional separation, high density lipoproteins appear as a zone showing noticeable heterogeneity with respect to both isoelectric point and molecular weight. Low density lipoproteins are resolved as a compact spot while very low density lipoproteins are visible as a long horizontal streak across the top of the electrophoresis gel. The implications of the technique for the analysis of lipoprotein patterns in pathological plasmas are discussed.