Functional studies of macrophages in zebrafish embryos.

(A, B) Dissecting microscope appearance of embryos before (A) and 2 hours after (B) intravascular micro-injection with a carbon particle suspension. Arrows in panel B indicate the accumulation of black carbon within cells in the ventral venous plexus. (C, D) Light microscope appearance of hematoxylin and eosin-stained sections of uninjected embryos (C) and embryos injected previously with carbon suspension (D). Cell with carbon in the cytoplasm, indented by the nuclei, indicated by white arrowheads. Other structures are gut and anal canal (black arrowhead), notochord (n), and yolk (y). Embryos were aged 2 dpf. Scale bars = 10 μm (C, D).