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PubMed · 14716076

Adapting the Quesant Nomad atomic force microscope for biology and patch-clamp atomic force microscopy.

S Besch·K V Snyder·P C Zhang·F Sachs
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Abstract

The Quesant Nomad atomic force microscope (AFM) was modified to produce a reliable patch-clamp AFM for demanding biologic applications. The AFM's laser optics forms the basis of a condenser that allows simultaneous Köhler illumination and AFM imaging on an inverted optical microscope. The original AFM scan head was replaced with plastic and glass to make it biologically inert. A bevel cut in the new scan head permits clearance for patch clamp pipets. Cantilevers are attached to the scan head with a quick setting silicone rubber that is readily removable. Software was developed to (a) automate a gentle approach and set a specific feedback force, (b) provide a mouse-driven control of the X-Y position of the probe tip and recall of saved locations, and (c) measure force-distance curves over user defined paths. Additional modifications were made to minimize mechanical noise. The patch-clamp AFM achieves 600 fA (3 kHz bandwidth) and 1 A RMS noise levels (10 kHz bandwidth). The correlation of electrical and mechanical information allows signal averaging and measures sub-Angstrom, sub-millisecond electromotile responses from cells.

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Cell MembraneCells, CulturedHumansMicroscopy, Atomic ForceMicroscopy, Phase-ContrastNanotechnologyPatch-Clamp TechniquesJournal ArticleResearch Support, Non-U.S. Gov'tResearch Support, U.S. Gov't, P.H.S.

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S Besch, K V Snyder, P C Zhang, F Sachs. 2003. Adapting the Quesant Nomad atomic force microscope for biology and patch-clamp atomic force microscopy.. https://doi.org/10.1385/cbb%3A39%3A3%3A195

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