Ultracentrifuge Concentration of Poliovirus and Effect of Calf Serum and Gelatin

Abstract

Studies were undertaken to determine the efficiency of concentration of poliovirus from tissue culture fluids in the ultracentrifuge. Under suitable sedimentation conditions most of the virus was concentrated to the lower portion of the centrifuge cup, but in the absence of calf serum was not present in a sediment adherent to the cup wall. Addition of calf serum resulted in formation of a firm, discrete pellet attached to the centrifuge cup wall which contained more than 95% of the virus. Further experiments indicated that the activity was associated with the globulin protein fraction of calf serum and that gelatin had a similar effect. Studies varying the amounts of calf serum and gelatin and duration of ultracentrifugation indicated that 2% calf serum or 0.06% gelatin and 3 hours centrifugation are minimal for effective concentration of poliovirus when sedimented at 78,000 times gravity in the number 30 rotor of the Spinco model "L" preparative ultracentrifuge.