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Updated: Jul 20, 2026

Crystallization of Proteins on Chip by Microdialysis for In Situ X-ray Diffraction Studies
Published on: April 11, 2021
Quantifying X-ray radiation damage in protein crystals at cryogenic temperatures
Jan Kmetko1, Naji S Husseini, Matthew Naides
1Physics Department, Cornell University, Ithaca, NY 14853, USA. kmetkoj@kenyon.edu
Abstract:
The dependence of radiation damage to protein crystals at cryogenic temperatures upon the X-ray absorption cross-section of the crystal has been examined. Lysozyme crystals containing varying heavy-atom concentrations were irradiated and diffraction patterns were recorded as a function of the total number of incident photons. An experimental protocol and a coefficient of sensitivity to absorbed dose, proportional to the change in relative isotropic B factor, are defined that together yield a sensitive and robust measure of damage. Radiation damage per incident photon increases linearly with the absorption coefficient of the crystal, but damage per absorbed photon is the same for all heavy-atom concentrations. Similar damage per absorbed photon is observed for crystals of three proteins with different molecular sizes and solvent contents.
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