A plant virus preparation in a fully crystalline state

[Letter] Specific proteins, believed to be the viruses themselves, have been isolated from plants infected separately with each of seven viruses of the tobacco mosaic and potato virus 'X' groups. Although these proteins have some properties in common with crystalline materials, and can be obtained in both solid and liquid anisotropic states, the solid preparations yet obtained lack the three dimensional regularity characteristic of true crystals. The particles of all these viruses are rod-shaped, and the connexion between this and the formation of fibres or pseudo-crystals has already been discussed