DISC ELECTROPHORESIS OF SUBCLASSES OF HUMAN SERUM LOW DENSITY LIPOPROTEINS

Serum chylomicrons, very low density lipoproteins (d < 1.006) and two classes of low density lipoproteins (1.006 < d < 1.019 and 1.019 < d < 1.050) were isolated from freshly collected normal human blood. Disc electrophoresis was performed with microquantities of these fractions using the standard spacer gel and with main gel concentrations of 1.9, 2.5, 3.0, 3.75, and 5.0%. Three different stains, namely, amido black 10B, Sudan black B and oil red O were employed for detecting the lipoprotein components in gels of 3.0, 3.75, and 5.0% concentration and sudan black B prestain was used for gels of 2.5 and 1.9% concentration. The results demonstrated that all the lipoproteins, except the chylomicrons, penetrated the standard spacer gel. In 3.0% gel, the very low density lipoproteins and the larger low density lipoproteins (1.006 < d < 1.019) were detected as separate bands behind the β-lipoprotein band. The relative migration distances in 3.0% gel of these lipoproteins were confirmed by investigating the electrophoretic behavior of synthetic mixtures of lipoproteins. The resolution obtained was superior to that previously reported with other electrophoretic methods and may find application in clinical investigations involving serum lipoproteins. © 1969.