VIEW ARTICLE

Techniques

Improved Purification of Rice Dwarf Virus by the Use of Polyethylene Glycol. Ikuo Kimura, Institute for Plant Virus Research, 959 Aoba, Chiba 280, Japan; Phytopathology 66:1470-1474. Accepted for publication 6 June 1976. Copyright © 1976 The American Phytopathological Society, 3340 Pilot Knob Road, St. Paul, MN 55121. All rights reserved.. DOI: 10.1094/Phyto-66-1470.

Purification of rice dwarf virus (RDV) was simplified and greater yield and infectivity of virus were obtained by precipitating RDV with polyethylene glycol 6000 (PEG 6000) from clarified extracts, than by previous procedures employing differential centrifugation. The optimal conditions for use of PEG 6000 were a pH of about 7.0, 0.3 M NaCl, 6% (w/v) PEG 6000, and incubation at 4 C for 4 hours. The optimal ratio of buffer solution to tissue (v/w) was five or six. Yields of purified virus were about 20-30% of that in the clarified extracts. Both clarified extracts and purified preparations contained (5.40-9.18) × 10⁸ virions per milliliter at the dilution end point for infectivity. Clarified extracts and purified preparations were quick-frozen in dry-ice ethanol and stored at –72 C for at least 18 months without detectable loss of infectivity.