Adapting atomic force microscopy for cell biology

We present details of our AFM modifications to produce an adaptable imaging system for the cell biologist. We have designed and validated a new inverted microscope interface and a scan head with increased Z-range, based upon the TopoMetrix Explorer AFM. We have utilised these changes, together with home-made glass ball cantilevers, to obtain topographical information over cells with large Z-dimension (over 15 μm high), and mapped calcitonin–calcitonin receptor binding forces in living bone cells. We conclude that modified AFM can be used to evaluate intermolecular events in living cells and that this approach will ensure general application to the study of receptor–ligand interactions under truly physiological conditions.