Abstract
1. The origin of phosphorous in T3 DNA was studied. From three types of P32-labeling experiments, whole labeling, host labeling, and medium-labeling, it was concluded that 84% of the phosphorous of T3 derived from host cells, 16% from the medium after infection and 0.5% from parental phages.
2. The distribution of phosphorous of different origins among phage DNA were studied with ECTEOLA-cellulose column chromatography. The ratio, P32 content to optical density at 260mμ, was compared among chromatograms of whole labeled, the hostlabeled, and the medium-labeled T3 DNA. There was no essential difference between them. So, it was concluded that phosphorous of any origin was distributed homogeniously among DNA molecules.
