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.
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机译：这项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。通过缓冲液中的原子力显微镜以动态模式观察了通过染色体扩散或通过分离技术获得的人类中期染色体。在适当的操作条件下，使用柔软的三角形悬臂梁（弹簧常数为0.08-0.4 N m（-1）），通过AFM获得了染色体扩展中固定染色体的清晰图像。为了对高度超过400 nm的孤立染色体进行成像，需要具有高长宽比的探针尖端的悬臂。 Q控制系统和动态力模式AFM中的采样智能扫描（SIS）系统的结合可用于获得分离染色体的高质量图像，其中清晰观察到约50 nm厚的球状或索状结构在每个染色单体的表面上。
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