Isolation of Polyoma Virus and Semliki Forest Virus from Tissue Culture Fluid by Continuous Flow Zonal Ultracentrifugation

Recently Anderson and his associates have described a series of high-speed zonal centrifuge rotors designed to allow small animal viruses to be isolated from large volumes of culture fluid without pelleting (1, 2). In these rotors the culture fluid flows as a thin Sheet across the surface of a liquid density gradient. Particles suspended in the fluid are rapidly sedimented out of the stream and become trapped in the gradient solution. Further centrifugation causes the particles to band at, or near, their isopycnic points. The capabilities of this type of rotor have been explored with adenovirus and T3 phage (2). This paper describes the application of continuous flow zonal centrifugation to the problem of concentrating and purifying large quantities of polyoma virus and Semliki Forest virus from c. 51. of tissue culture fluid.

A Beckman model ZU ultracentrifuge and a BXVI continuous flow zonal rotor were used in these experiments.