Density-Gradient Centrifugation

Abstract

In some cases, further separation of virus from the plant contaminants can be achieved by placing the clarified extract on top of a small volume of a sucrose solution in a centrifuge tube, the so-called sucrose cushion. Although the higher viscosity of the sucrose solution delays the virions reaching the bottom, the plant contaminants may be slowed down even more, resulting in a better separation in high-speed centrifugation.