Ion Conductance Microscopy(ICM)is useful for obtaining contact-free images of the surface topography and has been used for imaging cultured cells under liquid conditions.The Approach-Retract-Scan(ARS) mode is a new mode of ICM, which is especially powerful for imaging samples with steep slopes. To examine the applicability of ARS mode for imaging biological samples with greater height gaps, dense collagen fibril networks were examined by ICM.

The Park AFM provides highly sensi-tive force-distance data to observe interactions between single mole-cules through the low-noise control of the Z scanner movement. The force-distance results enable the assessment of binding interactions between single DNA molecules, RNA mole-cules, and proteins.

The ICM method gives useful information to cell researchers related with hpertrophy.

The True non-contact imaging mode of Park AFM insures minimal disruption of sensitive biological samples such as DNA molecures. The negligible interaction force between tip and smaple allows accurate heigh measurements of small bio-molecular smaples.