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Many processes of fundamental importance occur on a length scale not visible to the human eye. For example, a human hair which has a diameter of about 50 microns can just be seen; while cells which are typically microns in size require high quality light microscopes. Atoms are some then thousand times smaller! Magnification techniques - microscopy - have thus always been important in science. Until the early 1980's powerful electron microscopes provided the best resolving powers, however they required samples to be placed in a vacuum environment which meant biological specimens could only be imaged in the 'dead' state! The advent of microscopes which did not rely on lenses but instead a sharp scanning probe, revolutionised the way we have been able to look at biological systems. Real cells and biological molecules, such as DNA (see Figure 1) and neurons (see Figure 2), could be imaged alive under physiologically relevant conditions at high resolution.

This exhibit, in conjunction with Veeco (a leading manufacturer of AFM instrumentation: http://www.veeco.com) introduces you to the principles of atomic force microscopy; you will get to see at first hand how an AFM operates and understand the basics of the technique, with particular relevance to biomolecular imaging. It is important to bear in mind that AFM is not just an imaging technique; by measuring miniature forces it is also possible to look at the interaction forces between single molecules such as antibody, antigen binding and through further development one can also visualize the local electrical and electrochemical properties of a system.