Related Experiment Video
Updated: Jul 22, 2026

Assessing Two-dimensional Crystallization Trials of Small Membrane Proteins for Structural Biology Studies by Electron Crystallography
Published on: October 29, 2010
pycotem: An open source toolbox for online crystal defect characterization from TEM imaging and diffraction
Frédéric Mompiou1, Rui-Xun Xie2
1CEMES-CNRS and Université de Toulouse, Toulouse, France.
Abstract:
We present a series of tools working together that facilitate the determination of dislocation Burgers vectors and slip planes, interface plane normals and misorientation between two crystals from a series of Transmission Electron Microscopy (TEM) micrographs and diffraction patterns. To that purpose, we developed graphical user interface programs that allow crystal orientation determination from spot diffraction patterns taken at various tilt angles or from Kikuchi patterns crystal representation from stereographic projection plots and determination of geometrical features from series of conventional images taken at different tilt angles. We present working examples that allow a faster and easier way to analyse data that can especially be retrieved during in situ straining experiments where dislocations and grain boundaries need to be characterized. More generally, these tools target material scientists interested in daily microstructural characterization in TEM.
Related Concept Videos
X-ray Crystallography
Diffraction
Diffraction is the change in the direction of travel experienced by an electromagnetic wave when it encounters a physical barrier whose dimensions are comparable to those of the wavelength of the light. X-rays are electromagnetic radiation with wavelengths about as long as the distance between neighboring...
X-ray Diffraction of Biological Samples
According to Bragg's law, when X-rays strike the sample positioned on a stage, the rays are scattered by the electron clouds around the sample atoms. The X-ray diffraction or scattering is caused by constructive interference of the X-ray waves that reflect off the internal crystal...
Imperfections in Crystal Structure: Point, Line and Plane Defects
Imperfections in Crystal Structure: Stoichiometric Point Defects
Imperfections in Crystal Structure: Non-Stoichiometric Defects

