Atomic Force Microscope

Feedback adjusts the tip-sample interaction while the sharp tip scans the surface. When forces bend the cantilever, the laser and photodetector register that movement, allowing the system to maintain controlled contact or interaction during imaging. This control helps preserve nanoscale surface information and supports measurements of properties such as topography, adhesion, and stiffness.

The technique can examine biological structures without relying on fluorescent labels. This allows researchers to investigate cells, membranes, proteins, and other biomolecules through their surface organization and physical responses rather than requiring fluorescence-based visualization. The label-free approach is particularly relevant when studying mechanical properties or molecular interactions that may not be represented by a fluorescent signal.

Atomic Force Microscope measurements can be performed in air or liquid, including conditions near physiological environments. Liquid measurements are therefore relevant when researchers need to examine biological samples in a setting that better reflects their natural surroundings. Comparing these environments can help determine how surface organization, adhesion, stiffness, or molecular interactions appear under different experimental conditions.

A sharp tip attached to a flexible cantilever scans the biological sample while forces between the tip and surface cause cantilever movement. A laser directed at the cantilever and a photodetector measure that movement, and feedback regulates the interaction throughout the scan. The resulting measurements are used to map surface topography and characterize mechanical behavior at the nanoscale.

Researchers can apply the method to cells, membranes, proteins, and other biomolecules. It provides information about surface organization while also revealing physical characteristics such as adhesion and stiffness. This broad range makes the technique useful across studies of cellular structures, molecular assemblies, and biological materials, including samples examined in liquid or near-physiological conditions.

Measurements of surface organization, adhesion, stiffness, and molecular interactions provide physical information about biological samples. These results can support investigations of cell mechanics and disease mechanisms, as well as studies of biomaterials and drug development. The technique is valuable when research requires nanoscale structural or mechanical information from cells, membranes, proteins, or related biomolecules.