Rapid separation of DNAs by buoyant density in three-layer CsCl gradients.

The formation of three-layer CsCl gradients with a narrow middle layer containing the analyzed material allows the separation of macrospecies according to their buoyant densities during the first hours of centrifugation before equilibrium is attained. The method can be used for the isolation and purification of various DNA molecules, such as mitochondrial and plasmid DNAs.