Some factors influencing purification of potato virus A (PVA)

Potato virus A (PVA) was purified from mechanically infected plants Nicotiana tabacum cv Samsun by high speed centrifugation and subsequent isopycnic density gradient centrifugation in CsCl gradient. From different procedures tested 0.05 mol/l phosphate buffer (PBS) pH 8 seemed optimal for virus purification and 0.1 mol/l borate buffer pH 8.0 for virus storage; other pH of PBS, Tris and Hepes buffers were less suitable. Additives preventing virus aggregation were beneficial. The average yield ranged about 40 mg virus protein per kg starting material. The purified virus has remained serologically active after 30 days storage.