Concentration of solutes by freezing and centrifugation.

Abstract

The virus extraction rotor may be usefully applied for concentrating solutes such as low molecular weight substances, proteins, virus soluble antigens and picorna viruses by centrifuging frozen dilute solutions at moderately high rotor velocities in the virus extraction rotor which had been fitted with the filters and precooled to 0�C. To accomplish this a circular stainless steel container with inner diameter equal to the inner diameter of the insert minus 5 mm was made. The reason for the smaller diameter was to allow for the thickness of the set of filters which lined the inner surface of the rotor insert. A rod attached to a flat circular metal slab closed a hole in the base of the cylinder by means of an 0 ring in the metal slab. To conduct a concentration experiment the surface of the 0 ring was covered lightly with silicon grease and inserted in the groove on the bottom of the metal slab.