Absolute amount of ribonucleic acid in viruses.

ON the basis of work with plant virus strains, Knight1 expressed the view that all strains of virus contain the same quantity of nucleic acid. Recent experiments have shown that there exist a number of animal viruses which contain only ribonucleic acid. If one plots the percentage of ribonucleic acid against the particle weight of viruses containing ribonucleic acid, a hyperbola results. Thus in animal viruses also the absolute amount of ribonucleic acid seems to be the same, and coincides with the quantity found in most plant viruses. As the actual equation of the hyperbola is percentage ribonucleic acid × molecular weight of the virus = 2 × 108, the average weight of the ribonucleic acid in a single virus particle amounts roughly to two million times that of a hydrogen atom.