DEOXYRIBONUCLEIC ACID CYTOCHEMISTRY FOR AUTOMATED CYTOLOGY

Abstract

Fluorescent staining for intracellular deoxyribonucleic acid content is being investigated as a means of making automated measurements quantitative and reliable. Ambiguities regarding the role of sulfur dioxide in Feulgen staining chemistry have been resolved showing that: (a) SO2 does not covalently bind to the anilinium moieties of pararosaniline; (b) SO2 does promote the binding of pararosaniline within the nuclei of hydrolyzed cells; (c) SO2 also does not bind to dyes such as acriflavine used in fluorescent-"Feulgen" staining and (d) SO2 is not required for strong, nucleus-specific acriflavine staining of nuclei of hydrolyzed cells. These findings permit simplifications of the usual fluorescent-"Feulgen" procedures. Attempts to use fluorescent intercalating dyes as vital stains for deoxyribonucleic acid content have been unsuccessful.