Fig. 1. Characterisation of MyEnd monolayers and sites of cellular adhesion of VE-cadherin-coated microbeads by immunofluorescence (A-E), Alexa-phalloidin-staining (F), phase contrast microscopy (G-I) and scanning electron microscopy (J,K). MyEnd monolayers display a typical granular immunoreactivity for von Willebrand factor (A) and junctional immunostaining for VE-cadherin (B) and PECAM-1 (C). Adhering beads (D-F) are characterised by cellular recruitment of VE-cadherin (D, localised with antibody to cytoplasmic domain), ß-catenin (E) and F-actin (F). Staining of junctions (D,E) and stress fibers (F) is blurred because the optical plane is focussed on beads at the dorsal cell surface. Beads not associated with VE-cadherin, ß-catenin and F-actin probably represent the population of 20% of beads not firmly attached to cells. Scanning electron micrographs show small cellular protrusions abutting on the bead surface (J,K). Bars, 20 µm (A-C); 10 µm (D-I); 2 µm (J,K).