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The present paper describes the applicability of atomic force microscopy (AFM) to the observation of living cultured cells of an epithelial nature (human esophageal squamous cell carcinoma cells, or C7 subclone of KESC2 cells) in a culture medium. For this purpose, we made a fluid chamber system which allows a constant-speed perfusion of fluid at a regulated temperature in the chamber. Using this system, AFM images of living cells were successfully obtained for over one hour at time intervals of 2-4 min during continuous perfusion of the fresh culture medium. A series of these AFM images proved useful for examining the movements of cellular processes in relation to subcellular cytoskeletal elements. Time-lapse movie records produced by sequential AFM images further verify the reality of the cellular dynamics.

A self sensitive probe was composed of a piezoelectric tuning fork and a bent optical fiber tip for scanning near-field optical/atomic force microscopy. The topography, optical image and fluorescent spectrograph were successfully derived using the combined probe. The probe showed 1.1 nm vertical resolution at the tip-sample distance regulation. The combined probe showed single or twin resonant frequency peaks while the original tuning fork has only one resonant frequency of 32.7 kHz. In the twin peaks-case, results for various combination patterns suggested that one of the peaks is the response for a free arm of the tuning fork and the other is the response for the combined arm. The near-field acoustic effect was detected in the tuning fork probe as a small effect, but the effect was not detected in the combined probe.