Ushiki Tatsuo, Shigeno Masatsugu, Hoshi Osamu
Division of Microscopic Anatomy and Bio-imaging, Niigata University Graduate School of Medical and Dental Sciences, 1-757 Asahimachi-dori, Chuo-ku, Niigata 951-8510, Japan.
Nanotechnology. 2008 Sep 24;19(38):384022. doi: 10.1088/0957-4484/19/38/384022. Epub 2008 Aug 12.
The purpose of this study was to obtain three-dimensional images of wet chromosomes by atomic force microscopy (AFM) in liquid conditions. Human metaphase chromosomes-obtained either by chromosome spreads or by an isolation technique-were observed in a dynamic mode by AFM in a buffer solution. Under suitable operating conditions with a soft triangular cantilever (with the spring constant of 0.08-0.4 N m(-1)), clear images of fixed chromosomes in the chromosome spread were obtained by AFM. For imaging isolated chromosomes with the height of more than 400 nm, a cantilever with a high aspect ratio probing tip was required. The combination of a Q-control system and the sampling intelligent scan (SIS) system in dynamic force mode AFM was useful for obtaining high-quality images of the isolated chromosomes, in which globular or cord-like structures about 50 nm thick were clearly observed on the surface of each chromatid.
本研究的目的是在液体条件下通过原子力显微镜（AFM）获得湿染色体的三维图像。通过染色体铺展或分离技术获得的人类中期染色体在缓冲溶液中通过AFM以动态模式进行观察。在使用软三角悬臂（弹簧常数为0.08 - 0.4 N m⁻¹）的合适操作条件下，通过AFM获得了染色体铺展中固定染色体的清晰图像。对于成像高度超过400 nm的分离染色体，需要使用具有高纵横比探测尖端的悬臂。在动态力模式AFM中，Q控制系统和采样智能扫描（SIS）系统的组合对于获得分离染色体的高质量图像很有用，其中在每个染色单体表面清晰观察到约50 nm厚的球状或索状结构。
