Chromatographic studies on nucleic acids. 3. The nucleic acids of five strains of tobacco mosaic virus

ACIDS 513 this ratio were very crude by modern standards. What is more surprising is that this nucleic acid approximates so closely to a tetranucleotide, the maximum discrepancy being only 20%. It is evident, however, that, if all the nucleic acid particles in the preparation have a similar composition, the minimum 'molecular weight' of a polynucleotide must be at least 100,000. The inference is that the particles, as they exist in commercial yeast nucleic acid, are not all alike. SUMMARY A simple chromatographic method for the quanti- tative analysis of the bases of ribonucleic acids is described. The amount necessary for one analysis is about 0.1 mg. One hydrolysis only is needed and all the bases are recovered from single spots after chromatography on filter paper. Analyses of a specimen of yeast nucleic acid are given.