Potassium elemental distribution of (parts of) single fibroblast cells obtained from control patient ‘LR’ and Friedreich’s ataxia patient ‘SL’.

<p>For each case, 5 different fibroblasts were scanned. Boundaries of the fibroblasts are indicated, as well as their nuclei (if present). Scans were obtained in ‘Low Dose’ mode, with a step size of 100 nm and a dwell time of 50 ms. Maps are normalized to incoming intensity, 1s measuring time and are dead time corrected.</p

Background-corrected mean mass fractions of the elements P, S, Cl, K, Ca, Mn, Fe, Ni, Cu and Zn in the cytoplasm of 5 fibroblasts from control case ‘LR’ and FRDA case ‘SL’.

<p>Background-corrected mean mass fractions of the elements P, S, Cl, K, Ca, Mn, Fe, Ni, Cu and Zn in the cytoplasm of 5 fibroblasts from control case ‘LR’ and FRDA case ‘SL’.</p

Potassium and iron elemental distribution within control fibroblast case ‘PN’ (upper row) and FRDA fibroblast case ‘DJS’ (lower row).

<p>Scale bar indicates the background-corrected mass fraction in ppm, calculated from a mean cell thickness of 10 μm. Pixel size in the images is 55 nm; acquisition time for each pixel is 50 ms. Elemental maps were measured in ‘High dose’ mode and based on detector no. 5 (XIA05) only. All element maps were normalized to dead time, ring current and quantified using the Fundamental Parameter method, taking into account the ice layer thickness determined using the K-Kα/Kβ ratio. Red striped circles indicate areas with iron hot-spots, circles h1-h3 indicate exogenous iron hot-spots, white arrows spherical structures and red arrows fibre-like structures in the fibroblast cells.</p

Elemental distribution of P, S, Cl, Ca, Zn and Compton scatter within control fibroblast case ‘PN’ (upper row) and FRDA fibroblast case ‘DJS’ (lower row).

<p>Experimental conditions: see legend of <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0190495#pone.0190495.g002" target="_blank">Fig 2</a>. White dashed circle indicates the nucleus border. n1-2 indicate the presence of nucleoli.</p

Background-corrected mean mass fractions of the elements P, S, Cl, K, Ca, Mn, Fe, Ni, Cu and Zn within 1) entire cell body 2) nucleus and 3) cytoplasm of a single fibroblast from control patient ‘PN’ and Friedreich’s ataxia patient ‘DJS’.

<p>Background-corrected mean mass fractions of the elements P, S, Cl, K, Ca, Mn, Fe, Ni, Cu and Zn within 1) entire cell body 2) nucleus and 3) cytoplasm of a single fibroblast from control patient ‘PN’ and Friedreich’s ataxia patient ‘DJS’.</p

Potassium elemental distribution of (parts of) single fibroblast cells obtained from control patient ‘LR’ and Friedreich’s ataxia patient ‘SL’.

<p>For each case, 5 different fibroblasts were scanned. Boundaries of the fibroblasts are indicated, as well as their nuclei (if present). Scans were obtained in ‘Low Dose’ mode, with a step size of 100 nm and a dwell time of 50 ms. Maps are normalized to incoming intensity, 1s measuring time and are dead time corrected.</p

Prussian blue staining and TEM on FRDA fibroblasts.

<p>a) Light microscopic image of healthy human fibroblasts; b) TEM image of human fibroblast; c) negative Prussian blue staining of human control fibroblasts; d) positive Prussian blue staining of fibroblasts from Friedreich’s ataxia (FRDA) patients. Iron-rich regions are clearly present in the FRDA fibroblast cells as bright blue regions (indicated with arrows), while fibroblast nuclei and cytoplasm have a red and pink color, respectively.</p