Journal of Lipid Research, Vol. 12, 160-172, March 1971
Copyright © 1971 by Lipid Research, Inc.
The isolation of lipoproteins from human plasma by ultracentrifugation in zonal rotors
Henry G. Wilcox , Donald C. Davis , and Murray Heimberg
Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, Tennessee 37203
The major classes of lipoproteins were isolated from human plasma by ultracentrifugation in continuous density gradients using the Ti-14 and Ti-15 zonal rotors. Chylomicrons + VLDL, LDL, and HDL were separated from each other and from the more dense residual proteins (albumin fraction) of plasma by rate-zonal flotation in NaBr gradients in the density range 1.0-1.4. The chylomicron-VLDL fraction was subfractionated into constituent chylomicrons and VLDL by zonal ultracentrifugation in NaBr gradients in the density range 1.0-1.1. Plasma lipoproteins were analyzed for composition of lipids and content of protein, for electrophoretic mobility on paper, and for antigenic determinants by immunoelectrophoresis and immunodiffusion. Flotation constants (Sf) of the LDL and HDL were calculated from measurements made in the analytical ultracentrifuge. Lipoproteins isolated from plasma by zonal ultracentrifugation were identical by these criteria to lipoproteins isolated by the usual procedure of sequential ultracentrifugation in solvents of increasing density. The procedure of zonal ultracentrifugation is rapid, quantitative, and less laborious than sequential techniques. Lipoproteins isolated by zonal ultracentrifugation are relatively uncontaminated by other proteins and extensive washing is therefore unnecessary. Zonal ultracentrifugation is more than a preparative method for the plasma lipoproteins; it is also an analytical procedure in that a record is obtained of the distribution and quantity of the lipoprotein within the continuous density gradient.
Supplementary key words continuous density gradient lipoprotein protein lipoprotein lipids chylomicrons
Submitted on March 4, 1970
Accepted on November 13, 1970