Atomic Force Microscopy in the Life Sciences

Cells are highly organized in compartments and functional units down to the macromolecular level. The frameworks of these functional and structural units are either protein complexes or complexes of proteins with nucleic acids or with lipids. The recently completed map of the human genome and the systematic mapping of the proteins expressed in tissues and cells (proteomics) are part of a concerted effort to rapidly advance the understanding of the functions of macromolecular units and the cell. But proteomics reveals only the basic inventory of a cell and the inventory is insufficient to explain the function of each element and the orchestration of the components. As with Einstein’s image of the closed watch, understanding life is inconceivable without observing the structures behind function. Microscopy plays an important role by placing the molecular elements into a structural context. Because the pace of discovery of these elements has been increased substantially by proteomics, the need for more sophisticated microscopy has also substantially increased in recent years. Atomic force microscopy (AFM) plays a specific role in life science microscopy by allowing imaging to be combined with locally probing functions of macromolecular elements.