Overlapping staining of EB1 with p150^Glued or Clasp1 during EC tubulogenesis and presence of these microtubule tip complex proteins in a subapical band supporting the apical luminal surface while F-actin is localized along the basal surface. (A) Confocal microscope images derived from optical sections of vascular tube structures in 3D matrices. EB1 was co-immunostained with p150^Glued or Clasp1. EB1 (green) is colocalized with p150^Glued or Clasp1 (red) in EC tubes within 3D matrices. Scale bar is 20 μm. (B) ECs were cultured for 24 hours and 72 hours in 3D collagen matrices and fixed and stained for EB1, p150^Glued, or Clasp1 and F-actin. EB1, p150Glued, or Clasp1 distributed in a subapical domain, while F-actin was distributed basally. Stained samples were analyzed by confocal microscopy and representative images are shown. Scale bar is 20 μm.