Biomedical Application of Soft X-ray Microscopy with Special Reference to Spectromicroscopy

Abstract

Soft X-ray microscopy has great advantages over other types of microscopy on the observation of hydrated specimens at high spatial resolution below 100 nm, and on the elemental and molecular mapping using absorption characteristics. These advantages are particularly suitable for biomedical applications. A possible problem associated with observation of specimens at high spatial resolution in a hydrated environment is described and a strategy to overcome the problem is presented. The latter part of the present report deals with spectromicroscopy to obtain molecular distribution in biological specimens. DNA and protein distributions in isolated nuclei are examined following to the progression of apoptosis at high resolution, and the oxidation product is visualized in human hair in relation to calcium content.

Exploring the Mesoscopic Morphology in Mussel Adhesive Proteins by Soft X-ray Spectromicroscopy

“…Scanning transmission soft X-ray spectromicroscopy (STXM) has been developed as an alternative chemical-structure-sensitive imaging technique with high spatial resolution without selective staining or labeling. − X-ray microscopy relies on the spectroscopic contrast in the near-edge X-ray absorption fine structure (NEXAFS) spectrum. NEXAFS is very sensitive to the detailed chemical structure due to the close relationship between molecular bonding and the structure of the empty electronic states.…”