Fig. 2.

Immunofluorescence staining of aortic arch cells from 10-day-old embryos with an antibody against human von Willebrand factor. Specimens were reacted sequentially with anti-von Willebrand factor and fluorescein-conjugated goat anti-rabbit IgG. (a, b) Phase and fluorescence micrographs of a 30-µm-thick cryostat section; (c, d) phase and fluorescence micrographs of a 1-day-old culture prepared from the aortic arches; (e, f) as in c and d, respectively, but cultures were 3-day-old. Bar = 30 µm for b–f and 34 µm for a.