Fig. 5. Integrin binding of soluble GRGDSP and fibronectin. (A) Mean fluorescence ± s.d. demonstrating GRGDSP-biotin binding (10 µM) to indicated integrins expressed on GE11 cells analyzed by flow cytometry. (B) Mean fluorescence analyzed by flow cytometry, demonstrating binding of indicated integrins to different concentrations of soluble FITC-fibronectin. Binding to integrin β3 was shown previously in Fig. 3D. (C) Mean fluorescence demonstrating binding of soluble fibronectin-biotin (10 µg/ml) to indicated integrins upon competition with increasing concentrations of unlabeled fibronectin analyzed by flow cytometry.