In the last decade, the atomic force microscope (AFM) has emerged as a powerful tool for cell biology research giving ultrahigh resolution in real time under near physiological conditions. Studies revealing nanometer-scale details of the living cell, subcellular organelles, and biomolecules, previously impossible due to the resolution limits of light microscopes, are now accessible using the AFM. Pioneering work and instrumental development were carried out by the groups of Paul Hansma, University of California, Santa Barbara; and Gerd Binnig, IBM Physics, Munich. For the first time, in 1989, Binnig visualized the process of pox virus release on living cells. Meanwhile, many other groups contributed exciting new insights at the cellular and molecular levels using the AFM. This book contains examples of more recent studies done with instruments that have reached a stage of development in which the biological question and the preparation procedures become the major objectives.