ED-2+ and PB+ macrophages were identified (top, middle row), validating the presence of iron in well-differentiated macrophages. ED-1+ and PB− macrophages were identified (bottom row), confirming the absence of iron in monocytes/macrophages, and activated microglia. Brown = ED-2+ (top, middle) or ED-1+ (bottom), Blue = PB+, Background = nuclear fast red counterstain. Colocalized images, 40×, scale bar = 25 µm.