Investigation of chromatin folding patterns by atomic force microscopy

摘要

The chroznatin folding patterns in air and liquid were 8tudied by atondc force microscopy (AFM). A gentle water-air interface method was adopted to spread chromatin from interphase nucleus of chicken erythrocyte. The chrornatin was absorbed on APS-ndca surface and studied with AFM. Beads-on-astring were observed and many higher-order structures such as superbeads with dimensions 40～60nm in diameter and 4～7 nm in height were found to string together to make chromatin fibers. When sample spreading and absorbing time were shortened, higher-order chromatin fibers with 60～120 nm in width were observed in air as well as under water environment. These chromatin structures may reflect chromatin folding patterns in the living cells.