Figure 3

OPCs can be labeled with a multimodal MNP. ~60% of OPCs derived from a primary source exhibit uptake of a multifunctional MNP. (a) Phase contrast micrograph showing Perls’ iron staining of MNPs (arrows). (b) Z stack fluorescence micrograph confirming intracellular presence of MNPs, both perinuclear (crosshairs and dashed arrow) and cytoplasmic (arrow). Arrowhead indicates extracellular particle accumulation. OPCs were derived from primary rat cerebral cortex cultures and plated 24 h before MNP incubation: Fe₃O₄-PEI-RITC MNPs, 20 μg/ml, 24 h[54]. Cultures were then fixed (4% paraformaldehyde) and immunostained[54]. Further details can be found in Additional file1. Particle characteristics are detailed in Table 1. A2B5 is an OPC marker. RITC = rhodamine B isothiocyanate.