Abstract
The correlation of ultraviolet and Feulgen absorption after ribonuclease, cold perchloric acid, or ribonuclease plus perchloric acid treatments was investigated in fixed ascites tumor cells using microspectrophotometric methods. It was concluded from the measurements that the amount of ribonucleic acid resistant to 24 hour ribonuclease digestion is proportional to the amount of desoxyribonucleic acid revealed by Feulgen staining.