As the sedimentation velocity of lipid component is different from those of proteins and other cellular components, the membrane fraction can be separated from other components by a combination of differential centrifugation and sucrose density gradient centrifugation. Differential centrifugation can remove soluble proteins, most of the mitochondria, and nuclei. The sucrose density gradient can further separate different membrane components based on their different densities. However, multi-step centrifugation will reduce the yield of these membrane fragments. Therefore, steps of centrifugal separation should be minimized for membrane preparations.