Fig. 2.

A: Iron quantification (from phagocytosed USPIO) using a 2,2′-Bipyridine colorimetric assay as a standard reference. Cell iron uptake appears non-linear, best described by the 3rd order polynomial y = 2E-06x3 − 0.0009x2 + 0.1616x + 0.3092; R² = 0.999. All points represent triplicate mean ± SEM. B: Prussian blue visualised in J774 macrophages exposed to 40 µg/ml ferumoxytol USPIO and Perl stain; ×400 magnification light microscopy. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)