Cryogenic x-ray diffraction microscopy utilizing high-pressure cryopreservation

Phys Rev E Stat Nonlin Soft Matter Phys. 2014 Oct;90(4):042713. doi: 10.1103/PhysRevE.90.042713. Epub 2014 Oct 15.

Abstract

We present cryo x-ray diffraction microscopy of high-pressure-cryofixed bacteria and report high-convergence imaging with multiple image reconstructions. Hydrated D. radiodurans cells were cryofixed at 200 MPa pressure into ∼10-μm-thick water layers and their unstained, hydrated cellular environments were imaged by phasing diffraction patterns, reaching sub-30-nm resolutions with hard x-rays. Comparisons were made with conventional ambient-pressure-cryofixed samples, with respect to both coherent small-angle x-ray scattering and the image reconstruction. The results show a correlation between the level of background ice signal and phasing convergence, suggesting that phasing difficulties with frozen-hydrated specimens may be caused by high-background ice scattering.

Publication types

  • Comparative Study
  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Cryopreservation / methods*
  • Deinococcus
  • Ice
  • Image Processing, Computer-Assisted
  • Microscopy / methods*
  • Pressure*
  • Scattering, Small Angle
  • X-Ray Diffraction / methods*
  • X-Rays

Substances

  • Ice