Double-label immunofluorescence of Zip14 and ferritin in a normal control DRG and a DRG of an FA patient. (a)-(c) normal control; (d)-(f) FA; (a) and (d) Zip14 (Alexa488, green); (b) and (e) ferritin (Cy3, red); (c) and (f) merged images. Zip14 (a) and ferritin reaction products (b) show co-localization in the cytoplasm of several large and small neurons and in perineuronal satellite cells (arrows). Zip14 and ferritin fluorescence in neurons is heterogeneous. In the FA case (d-f), neuronal Zip14 (d) and ferritin (e) have shifted to a location beneath the plasma membrane while the central portion of the nerve cells (N) is devoid of reaction product. Zip14 fluorescence is present in satellite cells and a residual nodule (d, arrow). Ferritin fluorescence in multi-layer satellite cells and a residual nodule (e, arrow) is very prominent. Bars, 20 μm.