The Nature of the Specificity of Methyl Green for Chromatin.

Of all substances which bulk large in the chemical composition of cellular structures, desoxypentose nucleic acid is perhaps the most clearly demonstrable by application of cytochemical methods to cells. For each one of the three components of nucleotide residues there is a specific method which -enables the cytologist to visualize it on slides: the purines and pyrimidines have natural specific absorption in the ultra-violet spectrum; the Feulgen reaction reveals the desoxypentose; and the staining with basic dyes is an indication of the orthophosphoric acid component. It is this last specificity