Atomic force microscopy

Atomic force microscopy (AFM) is a scanning probe technique that allows imaging of biological samples with nanometer-scale resolution through the mechanical probing of their surfaces.
Instead of using light or electrons, AFM uses a sharp tip mounted on a flexible cantilever. As the tip scans the surface of the sample, forces between the tip and the sample (such as repulsive or attractive interactions) cause the cantilever to displace. These displacements are detected by laser deflection and translated into a high-resolution topographic image (see schematic below).

Because AFM can operate in liquids and under physiological conditions, it is particularly well-suited for imaging biological specimens, such as proteins, lipid membranes, and cells. In addition to topography, AFM can provide quantitative information about mechanical properties, such as stiffness, elasticity, and adhesion. This enables functional insights into biological structures.

A major recent advance is high-speed AFM, which dramatically increases imaging speed and allows visualization of dynamic processes in real time. This makes it possible to observe conformational changes of proteins, membrane remodeling, or molecular interactions in real time, capturing dynamic processes as they occur.

The imaging facility provides access to a Brucker NanoWizard UltraSpeed 3 AFM, enabling high-resolution and high-speed AFM measurements on a wide range of biological samples, along with training and support in sample preparation and experimental design.