Unlabeled and FePro labeled hMSC (A–C) and mNSC (D–F) cells.

<p>Microphotography of PB staining of non-labeled (A) and PB (B) and DAB-enhanced PB (C) staining of hMSC cells labeled with 100 µg/ml Fe and 3 µg/ml Pro for 4 h (B–C, show images taken from two different fields in the same slide). PB staining of non-labeled (D) and PB (E) and DAB-enhanced PB (F) staining of mNSC cells labeled with 100 µg/ml Fe and 3 µg/ml Pro for 4 h. Note the intracellular localization of FePro complexes that appear as blue (PB stain) and the dark brown granules (DAB enhanced PB stain). (A–F, bar = 100 µm).