SPECIALIZED SCANNING ION-CONDUCTANCE MICROSCOPE FOR IMAGING OF LIVINGCELLS

A specialized scanning ion conductance microscope (SICM) for imaging l iving cells has been developed from a conventional patch-clamp apparat us, which uses a glass micropipette as the sensitive probe, In contras t with other types of scanning probe microscope, the SICM probe has si gnificant advantages for imaging living cells: it is most suitable for imaging samples immersed in water solutions; and since the probe sens es ion current and does not need physical contact with the sample duri ng the scan, any preliminary preparation of cells (fixation or adheren ce to a substrate) is unnecessary. We have successfully imaged murine melanocytes in growth medium. The microscope images the highly convolu ted surface structures without damaging or deforming them, and reveals the true, three-dimensional relief of the cells. This instrument has considerable ability to operate, potentially simultaneously, in applic ations as diverse as real-time microscopy, electrophysiology, microman ipulation and drug delivery.