XANES spectroscopy: a promising tool for toxicology: a tutorial.

X-ray absorption near edge structure (XANES) spectroscopy can provide information on the oxidation state of metal ions within a biological sample and also the complexes in which it is found. This type of information could be of great use to toxicologists in understanding the mechanism of action of many toxic agents. The prospect of using a sophisticated physical technique such as XANES may be somewhat intimidating for those without a strong physical background. Here, we explain the concepts necessary to understand XANES spectroscopy at a level that can be easily understood by biological scientists without a strong physics background and describe useful sample preparation and data analysis techniques which can be adapted for a variety of applications. Examples are taken from an ongoing study of manganese in brain mitochondria and neuron-like cells.