SCANNING ION CONDUCTANCE MICROSCOPY OF LIVING CELLS

Currently there is a great interest in using scanning probe microscopy to study living cells. However, in most cases the contact the probe m akes with the soft surface of the cell deforms or damages it. Here we report a scanning ion conductance microscope specially developed for i maging living cells. A key feature of the instrument is its scanning a lgorithm, which maintains the working distance between the probe and t he sample such that they do not make direct physical contact with each other. Numerical simulation of the probe/sample interaction, which cl osely matches the experimental observations, provides the optimum work ing distance. The microscope scans highly convoluted surface structure s without damaging them and reveals the true topography of cell surfac es. The images resemble those produced by scanning electron microscopy , with the significant difference that the cells remain viable and act ive. The instrument can monitor small-scale dynamics of cell surfaces as well as whole-cell movement.