Density gradient solutions of metal ion chelate complexes

Abstract

Methods of forming a density gradient by applying a centrifugal field to a solution of one or more metal ion chelate complexes are disclosed. The density gradients are self-forming equilibrium gradients and are useful for separating biological particles by ultracentrifugation. Also disclosed are methods of separating biological particles according to their density. Also disclosed are density gradients of lipoprotein particles and one or more metal ion chelate complexes, wherein the lipoprotein particles are partitioned along the density gradient according to their particle density.