Purification of isometric particies from maize plants infected with rayado fino virus

The leafhopper-borne rayado fino virus of maize was purified from infected plant extracts by precipitation with polyethylene glycol and sucrose density gradient centrifugation. Empty protein shells and complete isometric particles of approximately 33 ± 1 nm and 30 ± 1 nm, respectively, separated in the gradient columns. Full particles showed ultraviolet absorbancy typical of nucleoproteins, and were infective when assayed in Dalbulus maidis .