This Peptide Competition Extracts prepared from chick embryo fibroblasts expressing FAK and plated on fibronectin were resolved by SDS-PAGE on a 10% polyacrylamide gel and transferred to PVDF. Membranes were blocked with a 5% BSA-TBST buffer for one hour at RT, then were incubated MBS626277 for two hours at RT in a 3% BSA-TBST buffer, following prior incubation with: no peptide (1), the phosphopeptide immunogen (2), the non-phosphopeptide corresponding to the immunogen (3), or, a generic phosphotyrosine containing peptide (4). After washing, membranes were incubated with goat F(ab’)2 anti-rabbit IgG HRP conjugate in 3% BSA-TBST buffer, and bands were detected using the Pierce SuperSignal™ method.The data show that only the peptide corresponding to MBS626277 blocks the antibody signal, thereby demonstrating the specificity of the antibody.