Low-cooling-rate freezing in biomolecular cryo-electron microscopy for recovery of initial frames

Abstract When biological samples are first exposed to electrons in cryo-electron microcopy (cryo-EM), proteins exhibit a rapid ‘burst’ phase of beam-induced motion that cannot be corrected with software. This lowers the quality initial frames, which least damaged by electrons. Hence, they commonly excluded or down-weighted during data processing, reducing undamaged signal and resolution reconstruction. By decreasing cooling rate sample preparation, either cooling-rate gradient increasing freezing temperature, we show frames for various protein virus can recovered. Incorporation reconstruction increases an amount equivalent using ~60% more data. Moreover, these preserve high-quality cryo-EM densities radiation-sensitive residues, is often very weak canonical three-dimensional The improved conditions easily achieved existing devices enhance overall structures.