WB (peptide competition) analysis of Jurkat cells treated with H2O2 (Lane 2-6) using GTX12869 ZAP70 (phospho Tyr315/Tyr319) antibody prior incubated with the non-phosphopeptide corresponding to the immunogen (Lane 3), a generic phosphotyrosine-containing peptide (Lane 4) the phosphopeptide immunogen (Lane 5) or, the phosphopeptide corresponding to ZAP-70 (pY315) (Lane 6) control. The data show that only the immunogen phosphopeptide blocks the signal, demonstrating the specificity of the antibody. The membrane treated with phosphatase (Lane 7) eliminates the signal further verifying that the antibody is phospho-specific.