Figure 4.

Procedure for measuring the binding of anti-integrin Igs to integrin receptors that became attached to adsorbed fibronectin during incubation with MC3T3 cells. Untreated and pretreated discs were coated overnight with various concentrations of fibronectin and incubated with MC3T3 cells for 2 h. After integrins were cross-linked to their bound ligand (adsorbed fibronectin), non-cross-linked cell proteins were extracted and the binding of anti-integrin Igs to cross-linked integrins was quantified by ELISA, as depicted schematically for the α₅β₁ integrin receptor.