Fig. 3.

VEGF-induced sprouting from the established, initial, microvessel.

(a) Timeline of the method (arrows indicate media renewal). (b) Phase-contrast images showing details of microvessels treated or not with 50 ng/mL VEGF-A (day 10). (c) Time-dependent sprout formation induced by VEGF-A treatment. (d) Immunostaining of an angiogenic sprout at day 10 showing the presence of a lumen and a tip/stalk/phalanx-cell-like organization (maximum intensity projection and orthographic view of CLSM images; green: actin; blue: nucleus; the dotted lines numbered 1, 2, and 3 indicate the cutting plane lines used for the orthographic view. A video of the 3D reconstructed image is provided as Supplementary Movie 1).