Abstract
A method of preparing ribonucleic acid (RNA) from tobacco mosaic virus (TMV) has been developed, based on denaturation of the protein part by guanidine hydrochloride and precipitation of RNA by neutral salt, avoiding extreme pH, high temperature and use of any organic solvent. The purity of the RNA thus obtained was as high as the RNA obtained by the sodium dodecyl sulfate method (Fraenkel-Conrat) or by the phenol method (Gierer and Schramm). The virus activity of the RNA alone obtained by the guanidine method was usually very low, while the RNA obtained by the phenol method was found as infectious as that reported by Gierer and Schramm. The molecular weight of RNA as determined by sedimentation and viscosity measurements was high (1.5-3×106); this value suggests that one TMV particle contains one single molecule of RNA. The molecule of RNA obtained by the guanidine method was found to be hydrodynamically less resistant than that obtained by the phenol method.
