Synchrotron X-ray chemical nano-imaging reveals iron sub-cellular distribution.

<p>The synchrotron X-ray fluorescence nanoprobe end-station installed at ESRF was designed to provide a high flux hard X-ray beam of less than 90 nm size (FWHM, full width at half maximum). The intensity distribution in the focal plane is shown in (A); dopamine producing cells were exposed <i>in vitro</i> to 300 µM FeSO₄ during 24 h (B). Chemical element distributions, here potassium and iron, were recorded on distinct cellular areas such as cell bodies (C), neurite outgrowths, and distal ends (D). Iron was found in 200 nm structures in the cytosol, neurite outgrowths, and distal ends, but not in the nucleus. Iron rich structures are not always resolved by the beam and clusters of larger dimension are also observed. Min-max range bar units are arbitrary. Scale bars = 1 µm.