Isotopic Studies on Ehrlich Ascites Cell Nuclei

Abstract

The method of isolation of the nuclei from Ehrlich ascites tumor cells was reported and the metabolic activity of the isolated nuclei was investigated. It was shown that ³H-uridine, ³H-cytidine and ³H-guanosine were phosphorylated to nucleotides and incorporated into the RNA of nuclei when they were incubated with the isolated nuclei. ³H-Adenosine was not phosphorylated and ¹⁴C-orotic acid was not converted to uridylic acid by nuclei. They were not taken up by the RNA of nuclei. ¹⁴C-Glycine incorporated into the proteins of nuclei when it was incubated with nuclei. Thus, the nuclei isolated from ascites tumor cells were found to maintain the enzymic activity to synthesize RNA and proteins.