Any of various methods of separation dispersions by the application of centrifugal force. In the case of density gradient equilibrium centrifugation, a gradient of densities is established in a centrifuge tube by adding a high molecular weight salt such as cesium chloride. The mixture of molecules to be studied is layered in the surface of the gradient and then centrifuged until each molecule reaches the layer in the gradient with a buoyant density equal to its own. In the case of density gradient zonal centrifugation, the macromolecules are characterized by their velocities of sedimentation through a preformed sucrose gradient. In this case the sedimentation velocity is determined by molecular size and shape.
Subjects: Genetics and Genomics.