Observations of cells and tissues by atomic force microscopy

The atomic force microscope (AFM) can reproduce the three-dimensional surface structure of non-conductive, biological specimens at high resolution. The present study shows our results of AFM observation of cells and tissues. Embedment-free sections of different tissues and organs were used for the AFM observation of the cellular surface and subcellular structures. The AFM images collected in air in a non-contact mode were comparable to those obtained by transmission electron microscopy of thin sections and deep-etched replicas, and by scanning electron microscopy. AFM images of living culture cells are also shown; these were collected in a contact mode in fluid. This technique enabled the direct three-dimensional observation of locomoting cells. Dynamics of cytoskeletal elements just beneath the cell membrane were also observed by APM. In conclusion, the AFM has great potential for providing valuable information on the structure and function of cells and tissues.