Atomic force microscopy produces faithful high-resolution images of protein surfaces in an aqueous environment.

The atomic force microscope has the potential to monitor structural changes of a biological system in its native environment. To correlate them with the biological function at a molecular level, high lateral and vertical resolution are required. Here we demonstrate that the atomic force microscope is capable of imaging the surface of the hexagonally packed intermediate layer of Deinococcus radiodurans in buffer solution with a lateral resolution of 1 nm and a vertical resolution of 0.1 nm. On average, these topographs differ from those determined by electron microscopy by <0.5 nm.