ABSTRACT
The very first isolations of histones by Kossel and his associates took advantage of the solubility of histones in diluted strong acids such as HCl or H2SO4, a method still used for extraction of histones in many laboratories. Isolated nuclei or crude chromatin preparations are preferred by most investigators to prepare histones and their fractions. Owing their solubility in dilute acids to their unique amino acid composition, protamines and histones were identified in cell nuclei of various organisms. Starch gel electrophoresis became a valuable tool for studies on heterogeneity and tissue specificity of histones. Technique for polyacrylamide gel electrophoresis of histones consists of the separation of their complexes with sodium dodecyl sulfate. Polyacrylamide gel and, to a lesser extent, starch gel electrophoresis permitted comparative investigations on histones from various sources. Histones can be quantitatively determined either by most of the usual protein assay techniques or some group chemical reactions.
