Atomic force microscopy (AFM)

Atomic force microscopy (AFM) uses a small probe (apex < 10 nm) to sweep and profile surfaces without altering or distorting them. In addition to high-resolution topographic imaging (x-y = 2 nm and z = 0.05 nm), it is possible to observe a biological system’s viscoelastic and/or chemical heterogeneity. The technique, being ideally suited to insulating and soft materials analysis, it can be applied to the study of biological systems (peptides, proteins, lipid bilayers, cellular membranes, biopolymers and biomaterials ...). Moreover, the AFM method is non-destructive, requiring no chemical marking or metallization of the sample.  
Unlike other forms of microscopy, AFM is not based on optics, which means that its resolution is not limited by the wavelength of light used. Since the technique does not require vacuum, biological samples can be kept alive. AFM’s applications in the field of biology are wide ranging and include: high-resolution imaging;manipulation of isolated biomolecules and; quantification of the interactive forces of biological complexes (ligand/receptor, antigens/antibodies etc.).

The major advantage of atomic force microscopy remains, given its imaging capabilities in aqueous conditions, the in situ observation of all interactions, biological reactions, or conformational changes. These observations are obtained in high resolution, in real time, and under physiological conditions (temperature, pH, ionic strength, etc.). AFM’s unique ability to observe and quantify dynamic phenomena has allowed the study of many biological systems in their native state. The many advances in AFM operating procedures, the improvement in sample preparation methods, the increased resolution of probes used and the expertise developed by highly qualified personnel make the atomic force microscope a major enabling tool for life sciences application.