title: Agarose gel electrophoretic evidence for domains of nuclear DNA linked with bonds cleavable with sulfhydryl molecules.
abstract: Complexes of intact nuclear DNA with proteins undissociable by 2.0 M NaCl and nonionic detergents were analyzed by agarose gel electrophoresis following physical or enzymatic fragmentation. Sulfhydryl molecules converted these DNAs (but not the bacteriophage lambda DNA) into smaller-Mr forms. Following limited restriction endonuclease digestion of complexes with PstI most of the nuclear DNA formed a high-molecular-mass band in the 60-110 kbp range. These 60-110 kbp fragments, releasable from the rest of nuclei by sulfhydryl molecules, have similar sizes to nuclear DNA loops detected by other techniques and may derive from supranucleosomal organizational units in the chromatin complex.
mesh_terms: D000818:Animals; D002467:Cell Nucleus / Q000032:analysis*; D004247:DNA / Q000032:analysis*; D004587:Electrophoresis, Agar Gel; D006801:Humans; D051379:Mice; D009690:Nucleic Acid Conformation; D013438:Sulfhydryl Compounds / Q000494:pharmacology*
chemical_list: D013438:Sulfhydryl Compounds; D004247:DNA