ADVANCES IN X-RAY MICROSCOPY FOR THE ANALYSIS OF TRANSITION METALS IN THE BRAIN

Collingwood, Joanna; Everett, James; Telling, Neil; Adams, Freddy

Abstract

Introduction: X-rays have the advantage that they have a short wavelength and can penetrate through a thick biological sample. It was the need to ‘see inside’ opaque objects, especially biological tissues, and to resolve features too small for optical microscopes or too thick for electron microscopes, that spurred the development of X-ray microscopes. Their much shorter wavelength means they are less hindered by the diffraction limit which has historically limited spatial observation to micro dimensions for visible or UV light. Many of the X-ray microscopy techniques that provide the greatest sensitivity and specificity for transition metals in biological materials are emerging at synchrotron X-ray facilities. Here, the extremely high flux available across a wide range of soft and hard X-rays, combined with state-of-the-art focussing techniques and ultra-sensitive detectors, makes it viable to undertake direct imaging, chemical and mineral speciation of trace element concentrations in biological materials. Methods: Synchrotron X-ray methods for characterization of trace metal accumulations and metal-binding species are compared and placed in context with other techniques for trace metal analysis in tissues, taking into account the sample preparation requirements and the relative advantages and disadvantages of each technique for analysis at regional, cellular, and sub-cellular spatial resolution.Conclusions: X-ray microscopy meets the criteria of complementing data from existing modalities while providing totally unique views of cells and tissues. In particular, it allows the semi-quantitative or even quantitative imaging of numerous elements and elemental compounds within intact biological cells down to the level of nanometre-sized objects and structures. The combination of the superior penetration power of X-rays, and their capacity for high sensitivity quantitative elemental analysis at high spatial resolution, creates a unique tool with capabilities that other microscopy techniques based on electron or light microscopy cannot provide. While X-ray techniques need synchrotron radiation sources for optimum performance, they can also be implemented with micro-focus laboratory sources at reduced spatial resolution and sensitivity. With synchrotron X-ray microscopy, comparatively non-destructive elemental imaging and speciation of iron and other transition metals in brain tissue is possible with sub-cellular spatial resolution, specificity and sensitivity unmatched by any other imaging techniques.E100E277

Citation

Collingwood, J., Everett, J., Telling, N., & Adams, F. (2017, May). ADVANCES IN X-RAY MICROSCOPY FOR THE ANALYSIS OF TRANSITION METALS IN THE BRAIN. Poster presented at Seventh Congress of the International BioIron Society (IBIS) Biennial World Meeting (BioIron 2017)

• Presentation Conference Type: Poster
• Conference Name: Seventh Congress of the International BioIron Society (IBIS) Biennial World Meeting (BioIron 2017)
• Start Date: May 7, 2017
• End Date: May 11, 2017
• Deposit Date: Jun 7, 2023
• DOI: https://doi.org/10.1002/ajh.24812
• Publisher URL: https://onlinelibrary.wiley.com/doi/10.1002/ajh.24812
• Additional Information: Poster information for this session can be found on page E277 of this conference publication.