SUMMARY: A rapid centrifugation method for purifying foot-and-mouth disease virus (FMDV) combined an isodensity separation below a moving zone separation in the same tube. Two ml. of crude infectious fluid were introduced over a 3 ml. nonlinear CsCl gradient in a swinging bucket rotor. This preformed gradient provided a gradual increase from density 1.0 to 1.3 g./ml. and a step from 1.3 to 1.6 g./ml. After centrifugation for 4 hr. at 37,000 rev./min. (120,000 g) and 4°, a 1 mm. wide light scattering zone was observed with type A virus near the bottom, clearly separated below debris extending from density 1.3 to the meniscus. The narrow light scattering zone contained (40 ± 12%) of the FMDV infectivity and its CsCl isodensity was 1.43 ± 0.01 g./ml. Southern bean mosaic virus and bacteriophage øX174 behaved similarly and were useful as density markers. Virus suspensions concentrated an average of 8 fold retained (47 ± 16) % of their infectious units and were studied in the analytical ultracentrifuge directly. Dialysed concentrated virus revealed characteristic particles in an electron microscope. Exposure to concentrated impure CsCl decreases the stability of the infectivity to such an extent that in 40% CsCl its half-life is about 4 days.


Article metrics loading...

Loading full text...

Full text loading...

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error