Electron beam damage studies of synthetic 6-line ferrihydrite and ferritin molecule cores within a human liver biopsy

Micron. 2006;37(5):403-11. doi: 10.1016/j.micron.2005.12.009. Epub 2006 Jan 19.

Abstract

In order to achieve an accurate understanding of the crystal structure of 6-line ferrihydrite (6LFh) and ferritin molecule cores within a human liver biopsy using transmission electron microscopy (TEM), electron beam damage should be considered. For the case of 6LFh, the electron energy loss near-edge structure (ELNES) of core ionisation edges in the electron energy loss spectrum (EELS) combined with multiple linear least-square (MLLS) fitting of reference spectra together with analysis of selected area electron diffraction (SAED) patterns suggests that the iron in 6LFh is solely octahedrally coordinated Fe3+. With increasing electron dose, an increasing percentage of this octahedrally coordinated Fe3+ migrates to tetrahedral sites. When the dose exceeds 3 x 10(8) electrons/nm2, Fe2+ is found to be present in the material. This method also indicates that the iron in ferritin molecule cores within a human liver biopsy is the same as in 6LFh, entirely Fe3+ in octahedral coordination with oxygen. Again the percentage of octahedrally coordinated Fe3+ decreases as the accumulated electron dose increases and Fe2+ is produced in the liver biopsies when the electron dose exceeds 10(6)electrons/nm2.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Biopsy
  • Electrons*
  • Ferric Compounds / chemistry*
  • Ferritins / chemistry*
  • Ferritins / ultrastructure
  • Humans
  • Liver / metabolism*
  • Liver / pathology
  • Male
  • Microscopy, Electron, Transmission

Substances

  • Ferric Compounds
  • ferric oxyhydroxide
  • Ferritins