[Dissociation and decompactization of chromatin by heparin in a medium of "physiologic" ionic strength].

It has been shown for the first time that heparin, one of the natural polyanions, is capable of dissociating the histones H1, H2A and H2B from chromatin in a medium of "physiological" ionic strength: 0.15 M NaCl + 0.7 mM Na-phosphate buffer, pH 7.0. Under the same conditions heparin produces chromatin fractionation, leading to the appearance of slow-sedimenting DNA, augments viscosity and reduces turbidity of chromatin suspension. This evidences the decompactization of deoxyribonucleoprotein fibrils.