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TY - JOUR AU - Rattner, J. B. AU - Hamkalo, B. A. PY - 1978 DA - 1978/01/01 TI - Higher order structure in metaphase chromosomes JO - Chromosoma SP - 373 EP - 379 VL - 69 IS - 3 AB - The morphology of metaphase chromosome-derived chromatin fibers released from cells by non-ionic detergent cell lysis in the presence of divalent cations has been studied by electron microscopy. In these preparations the euchromatic arms appear as a series of loops, 200–300 Å in diameter, which are composed of closely-apposed nucleosome arrays. The higher order fiber in chromosomes derived from detergent-lysed cells appears to be less stable than chromatin fibers obtained by mechanical cell lysis. The fiber breaks down into a series of non-uniform nucleosome aggregates (superbeads) and finally to chromatin in a beads-on-a-string morphology upon incubation at 31° for 20 min. These observations allow us to suggest a relationship between uniform thick fibers, superbead-containing fibers, and beads-on-a-string chromatin within metaphase chromosomes. SN - 1432-0886 UR - https://doi.org/10.1007/BF00332140 DO - 10.1007/BF00332140 ID - Rattner1978 ER -