Fig. 4. Determination of relative amount of VE-cadherin exposed on the dorsal surface of MyEnd monolayers assayed by the capacity of the dorsal surface of formaldehyde-fixed monolayers to bind the mAb 11D4.1 antibody specific for VE-cadherin ectodomain. In untreated monolayers (2) surface-bound IgG heavy chain signal is slightly reduced as compared to monolayers treated for 30 minutes with 10 µM cytochalasin D (3) and 10 µM A23187 (4). MyEnd not incubated with mAb 11D4.1 (1) and HUVECs incubated with mAb 11D4.1 (5) served as negative controls.