Chromosomes consist of single DNA‐histone fibres (with non‐histone protein and RNA in
the active regions) that are packed by folding or coiling into fibres which can be classified …

Chromatin prepared by brief digestion of nuclei with micrococcal nuclease, and extracted in
0.2 mM EDTA, appears in the electron microscope as filaments of about 100 A diameter …

Electron microscopic and biochemical studies demonstrate that the fundamental structure of
chromatin depleted of lysine-rich histones is composed of a flexible chain of spherical …

X-ray diffraction photographs have been obtained of unoriented gels of chromatin prepared
by brief digestions of rat liver nuclei with micrococcal nuclease. At low concentration (20 …

The nucleosome model of chromatin structure now seems to be so firmly established as to
require little defense. Particles which can be visualized in the electron microscope, released …

There now seems to be little doubt that DNA in the nucleus of eukaryotic cells is in the form
of very long, continuous molecules, probably thousands of times as long as the largest …

The organization of nucleosomes in higher order chromatin structures has been studied by
electron microscopy of chick red blood cell nuclei. Chromatin appears as a thick fiber with an …

Many studies have led to the proposal of a subunit structure for chromatin similar to a string
of beads. Each bead is thought to contain 200 base pairs of DNA coiled on the outside of a …

Publisher Summary The electron micrographs of the cell nucleus and chromosomes provide
at first sight a confusing and not very informative picture. The reasons for this are not …

A model is proposed for the structure of DNA in chromatin sub-units. Each sub-unit is
proposed to contain two turns of an inner coil, with a pitch of about 40and an external …