Fig. 2. Quantitative analysis of HUVEC adhesion to EphB4-Fc-and ephrinB2-Fc-coated adhesive and non-adhesive surfaces. (A) HUVECs were seeded on top of adhesive (left) or non-adhesive (right) plastic surfaces coated with ephrinB2-Fc (160 ng/mm²) or EphB4-Fc (160 ng/mm²). Adhesion of cells was assessed by digitally measuring the cell-covered area of the coated surface after 24 hours (representative pictures are shown below). HUVECs avoid adhesion to ephrinB2-Fc-coated adhesive plastic. In turn, EphB4-Fc promotes adhesion to non-adhesive plastic. (B) Dose dependency of ephrinB2-Fc-mediated anti-adhesive effects on HUVECs. EphrinB2-Fc (dark bars) inhibits HUVEC adhesion with an EC₅₀ of 12.2 ng/mm² and a hill slope of –1.5 (representative pictures are shown below). Clustering of ephrinB2-Fc (light bars) induced a left shift with an even steeper dose-response curve (EC₅₀: 8.5 ng/mm²; hill slope: –2.4) (insert). The figure shows the mean±s.d. of one out of three experiments with similar results. The coverage of control coated adhesive plastic was set to 100%. ***P<0.001 compared with corresponding control. Bars, 200 µm.