A CYTOCHEMICAL STUDY OF THE SOLUBILITIES OF THE HISTONES OF FIXED NECTURUS LIVER

Abstract

Evidence for heterogeneity in solubility properties of the histones of fixed Necturus liver was obtained by extracting freeze-methanol-substituted tissue with 2-10% perchloric acid, ethanol-HCl, or 0.02 N HCl, postfixing in formaldehyde then staining with the Alfert-Geschwind method for basic proteins and measuring the dye bound to nuclei by microspectrophotometry. Data was obtained which can be interpreted as indicating that each of the acids extracts a discrete portion of the histone. Information from experiments based on sequential extractions with two different reagents suggests that the portions extracted may represent different subfractions, perhaps corresponding to histone subtypes differing in relative content of arginine and lysine and in other properties.