Abstract Reconstitution of common tobacco mosaic virus (TMV) protein with the ribonucleic acid (RNA) of the chemically produced strains nos. 256, 257, and 314 proceeded to a similar extent as with common TMV-RNA. HR-RNA reconstituted slightly less well than common TMV-RNA. All reconstituted viruses without regard to the strain origin of their RNA showed a similar stability under mechanical stress and in weak alkaline solutions. The infectivities of the mixed reconstituted viruses were much higher than the infectivity of the RNA donor strains and similar to the infectivity of the protein donor strain, that is, of common TMV.