Atomic force microscopy of living cells

This paper is a review of our results of the application of atomic force mi croscopy (AFM) to the three-dimensional observation of living cells. First, we showed AFM images of living cultured cells in fluid. Contact mode AFM o f living cells provided precise information on the shape of cellular proces ses (such as spike-like processes or lamellipodia) at the cellular margin. The contour of cytoskeletal elements just beneath the cell membrane was als o clearly observable on the upper surface of the cells. Secondly, we showed the data on the discrepancy between the AFM images of living cells and fix ed cells. These findings were useful for evaluating AFM images of living ce lls. Finally, we described the time-lapse AFM of living cells. A fluid cham ber system enabled us to obtain AFM images of living cells for over 1 h at time intervals of 2-4 min. A series of these AFM images were useful for exa mining the movements of cellular processes in relation to subcellular cytos keletal elements. Time-lapse movies produced by sequential AFM images also gave a realistic view of the cellular dynamics.