Abstract
An atomic force microscope (AFM) enables to describe the surface structure by tracing the sample surface with a probe (needle) even in solution. Therefore, it is expected that the movement of cell surfaces can be captured in culture medium at high resolution equivalent to that of an electron microscope. However, in order to detect the endocytosis and the lamellipodia moving on the cell surface, it is necessary to scan the probe faster than their movement. The AFM (Olympus BIXAM) used captured an area of 6 μm × 4 μm at a speed of 1 frame / 10 seconds. Such a scan rate may no longer be sufficient, but the movement of lamellipodia extending from the cell surface and of the actin filaments just below the cell membrane were successfully captured. In addition, AFM has succeeded in revealing the intracellular fine structures of cultured cells and of cells in tissues by using unroofing technique and cryo–sections (Tokuyasu method) respectively for sample preparation.
