Fritzsche W, Schaper A, Jovin T M
Department of Molecular Biology, Max Planck Institute for Biophysical Chemistry, Goettingen, Germany.
Scanning. 1995 May-Jun;17(3):148-55. doi: 10.1002/sca.4950170305.
We have adapted specimen preparation techniques of conventional electron microscopy for visualizing chromatin structures in the scanning force microscope (SFM) in air and in liquid. The beaded substructure of the nucleoprotein filament was obtained after hypotonic lysis of chicken erythrocytes and air drying, whereas supranucleosomal structures were preserved after treatment of cell nuclei with detergent. In the latter case, the nucleosomes were still distinct but appeared more condensed. A modified droplet diffusion-spreading technique of chromatin from Namalwa cells (a human B-lymphoid line) yielded a uniform filamentous morphology and similar fiber appearance. A reversible swelling of spread chromatin was observed upon exposure of air-dried samples to solutions differing in salt concentrations.
我们采用了传统电子显微镜的样本制备技术，以便在空气和液体环境下，通过扫描力显微镜（SFM）观察染色质结构。对鸡红细胞进行低渗裂解并空气干燥后，可获得核蛋白丝的串珠状亚结构，而用去污剂处理细胞核后，超核小体结构得以保留。在后一种情况下，核小体仍然清晰可辨，但显得更为浓缩。对Namalwa细胞（一种人类B淋巴细胞系）的染色质采用改良的液滴扩散铺展技术，得到了均匀的丝状形态和类似的纤维外观。将空气干燥的样本暴露于盐浓度不同的溶液中时，观察到铺展染色质发生了可逆的肿胀。
