A Useful Accessory to the Zeiss Mechanical Stage for Oil Immersion Microscopy

Crystallia ribonuclease has no marked proteolytic activity, since digestion of sections with this enzyme produces no appreciable decrease in the intensity of the cytochemical tests for arginine and tyrosine. Cytoplasmic basophilia is unaffected by treatment with cold trichloracetic acid or with boiling alcohol-ether mixture. Mononucleotides and fatty acids thus have nothing to do with basophilia. Digestion of sections with desoryribonuclease has no effect on the alkaline phosphatase or arginine tests, while it supresses the Feulgen reaction and the affinity of the chromatin for basic and for some acid dyes.