THE CYTOCHEMICAL ESTIMATION OF PROTEIN USING NAPHTHOL YELLOW S, AND COMBINED MEASUREMENT OF DEOXYRIBONUCLEIC ACID

Abstract

The quantitative staining response to the naphthol yellow S technique described by Deitch (1955) has been determined on normal mammalian red blood cells using scanning microdensitometry. It is concluded that these cells can be used as a standard of reference for this type of protein when making comparisons between various types of cell populations. The possibility of mutual interference following the application of both the Feulgen and naphthol yellow S techniques to the same preparation has been investigated using mouse ascites tumour cells and leucocytes. In this material it was found that the Feulgen method led to the loss of binding sites for naphthol yellow S, but that the application of the latter did not result in the extraction of deoxyribonucleic acid (DNA). By taking naphthol yellow S absorption readings before applying the Feulgen technique, this difficulty can be avoided, and both the protein and DNA complements of individual cells can be measured without error through loss of either component.