Peculiarities of cytochemical properties of cancer cells as revealed by study of deoxyribonucleoprotein susceptibility to Feulgen hydrolysis.

Chromatin of human squamous carcinoma cells reacts more intensively to short (1-2 min) acid hydrolysis in the Feulgen reaction and is, after such treatment, more intensively stained by Schiff reagent than chromatin of normal cells of the same origin. To reveal this difference in chromatin properties the use of a fluorescence variant of the Feulgen reaction is necessary because nuclei-binding of Schiff reagent after such short hydrolysis is so weak that the amount of the stain bound by means of absorption technique is hardly possible. The use of increased sensitivity of cancer cells chromatin to acid hydrolysis for cancer cytodiagnosis is suggested, especially for the diagnosis of so called diploid cancers for which detection on the basis of deoxyribonucleic acid content determination is impossible.