1010 



ADVEA^TURES IN RADIOISOTOPE RESEARCH 



O = control 

 X = cancer 



Fig. 10. Loss of "C by the hemin of red corpuscles of control 

 mice and mice inoculated with ascites cells 10 days prior to injection 

 of glycine-^*C-2. The figure is showing the effect of cancer on the 



formation of red corpuscles. 



content is present in the nucleic acids which are predominantly composed 

 of ribosenucleic acid. In the virus Tg we find DNA to contain almost all 

 phosphorus present. If we infect Escherichia coli with T^ bacteriophage 

 in a synthetic medium during the latent period, at a time when division 

 of bacteria cells had stopped, protein and DNA synthesis will still go on, 

 the newly formed constituents being almost exclusively found in the 

 virus formed as a result of infection. As to the phosphorus atoms of 

 nucleic acid, as seen in Fig. 11, these are to a very large extent found now 

 in the DNA molecules. 



If we wish to know the origin of the phosphorus atoms of the virus, 

 whether they are derived from the phosphorus atoms present in the host 

 prior to infection or derived from the medium, we grow bacteria contain- 



Table 1. — Activity of Phosphatide 

 Phosphorus of Milk and Organs of a Goat 



4.5 hr after administration of labelled sodium pliosphate. 



