James Chen

Super-resolution Single-Particle Electron Microscopy

The Nyquist Frequency represents the information cut-off in discrete signal sampling. In single-particle EM, the Nyquist Frequency dictates the highest resolution achievable in 3D reconstruction. However, this information upper-limit stands only for a single image. When the same object is recorded into a movie stack with random subpixel frame translations, the image ensemble actually contains information beyond the Nyquist Frequency. In this work, an algorithm is proposed and implemented to retrieve such information from 2D image series. Its application in single-particle cryo-EM is demonstrated on an experimental movie dataset, in which image stacks recorded at 2.2 Å/pixel have enabled the 3D reconstruction reaching 3.3 Å resolution.