The nucleic acid content of mouse ascites tumor cells

Abstract

Nucleic acid determinations were carried out on cells of Ehrlich ascites tumor of mice. Ascites fluid was withdrawn a certain period of time after the inoculation of 0.8 × 10 6–39 × 10 6 cells, and the nucleic acid content was determined per ml fluid and per cell after counting the number of cells. The following results were obtained: 1. 1. The content of nucleic acids in 65 animals was on an average: NA = 4.09 × 10 −6 μg P per cell PNA = 2.68 × 10 −6 μg P per cell DNA = 1.42 × 10 −6 μg P per cell PNA/NA = 65.6 per cent PNA/DNA = 1.94 The variability between animals was low (14.1 per cent for PNA, 21.3 per cent for DNA). 2. 2. In spite of the variation in the inoculated number of cells from 0.8 × 10 6 to 39 × 10 6, and a corresponding decrease in the median survival time from 11 to 5 days, there was no difference in cell nucleic acid content observed when sacrificing the animals on the median survival time ± 2 days. 3. 3. Starvation for 48 hrs had no effect on the PNA content of the tumor cells in spite of having a deteriorating action on the general condition of the animals. 4. 4. The isolation of nuclei performed with 1 per cent citric acid had no influence on the DNA content, the values per nucleus were the same as per whole cell. 5. 5. The DNA content of tumor cells was about twice and the PNA content about fivefold the value obtained on non-tumorous exudate cells, which were: PNA = 0.44 × 10 −6 μg P per cell DNA = 0.77 × 10 −6 μg P per cell PNA/DNA = 0.59 6. 6. U.V. examination at 257 mμ showed a rather uniform and high absorption in ascites tumor cells, while solid Ehrlich carcinoma cells had highly varying absorption.