Video imaging of biomolecular processes by high-speed AFM

The imaging rate of conventional atomic force microscopy (AFM) is too low to capture the dynamic behavior of biomolecules. To overcome this problem, we have been developing various devices and techniques, including small cantilevers and high-speed scanners. The feedback bandwidth in the tapping-mode now exceeds 100 kHz and hence the maximum possible imaging rate reaches 25 frames per sec (fps). Importantly the tip-force exerting onto the sample is dramatically reduced. Thus, it is now possible to take video images of dynamically moving protein molecules in action without disturbing their function, including walking myosin V molecules along action tracks.