Measuring Metals in Complex Biological Systems

This chapter presents a conceptual overview of techniques for element imaging in biological specimens. Mass spectrometric techniques, particle and photon-induced X-ray emission techniques as well as X-ray and electron absorption techniques are described. In addition, it discusses frequent methodological issues common to elemental bioimaging in all of these techniques. These concern differential leaching of analyte species from distinct biological structures in contact with water and the use of reference parameters correcting for nonhomogeneous material density and nonhomogeneous instrument sensitivity. The use of 3D atlases of element concentrations for hypothesis generation is exemplified by manganese in the rat brain.The data reported in this chapter were acquired from healthy tissue and illustrate the potential of measurement methods, which can have a major impact in clarifying the role of heavy metals in infectious disease. The examples described have been selected from among various applications of element imaging and may indirectly help infection biologists choose appropriate analytical strategies for their experiments.