Dose symmetric electron diffraction tomography (DS-EDT): Implementation of a dose-symmetric tomography scheme in 3D electron diffraction

Ultramicroscopy. 2023 Sep 16;255:113857. doi: 10.1016/j.ultramic.2023.113857. Online ahead of print.ABSTRACTBeam sensitive nanomaterials such as zeolites or metal-organic frameworks (MOF) represent a great challenge for crystallographic structure determination and refinement. The strong electron-matter interaction and the high spatial resolution achievable make electron diffraction the technique of choice for particles of sizes below a micrometer and many different 3-dimensional electron diffraction (3D ED) techniques have been developed in recent years. Nevertheless, beam sensitivity of the samples can lead to the crystal structure being damaged during the data acquisition impeding the determination of its structure. A simple way to reduce beam damage is to lower the dose during the experiment. However, this implies weaker diffraction intensities which can become problematic for the exploitation of the data. In order to obtain complete data sets with strong intensities without damaging the crystals, we developed the dose symmetric electron diffraction tomography (DS-EDT) method, combining the low-dose electron diffraction tomography (LD-EDT) technique with the dose-symmetric tomography scheme known from cryo-EM. In order to reduce the dose on an individual crystal and still obtain enough data for a structure solution and refinement, we partition the dose over several crystals. The individual datasets are then merged in order to achieve the necessary completeness. On two test...
Source: Ultramicroscopy - Category: Laboratory Medicine Authors: Source Type: research