Stereo electron microscopy of the 25-nm chromatin fibers in isolated nuclei.

Abstract

Thin sections (0.1-0.25 micron) of isolated chicken erythrocyte nuclei were examined at various tilt angles. Stereo pairs of electron micrographs document the parallel alignment of 25-nm chromatin fibers adjacent to the nuclear envelope, and demonstrate a fiber substructure consistent with close-packed arrays of nucleosomes.