A new computational method dramatically increases the resolution of atomic force microscopy. Under standard physiological settings, the approach exposes atomic-level data on proteins and other biological structures. It gives up a new world of possibilities in cell biology, virology, and other microscopic processes.
In physics, atomic force microscopy can efficiently resolve atoms on solid surfaces of silicates and semiconductors. The equipment has the precision to do so in principle. On the other hand, biological molecules have many tiny components that wiggle, obscuring AFM images. The scientists used a notion from light microscopy called super-resolution microscopy to solve the problem.
The spontaneous changes of biological molecules captured throughout the AFM scan produced similar spreads of positional data rather than triggering fluorescence. They conducted a series of tests and computer simulations to understand the AFM imaging process better, extracting maximum information from the atomic interactions between the tip and the material. Using the super-resolution analysis technique, they could obtain quasi-atomic resolution images of the moving molecules.
Researchers can now study biological molecules under physiologically relevant conditions thanks to a new AFM technique. AFM reanalysis of an aquaporin membrane protein produced a much sharper image that matches X-ray crystallography structures. AFM can generate images of single molecules, whereas X-ray crystallography and cryo-electron microscopy rely on averaging data from large numbers of molecules.
Related Content: Light-Field Microscopy Volumetric Imaging