A working concentration of 500 µg/mL for triple FLAG® peptide is typically used for competitive elution of FLAG® containing proteins from anti-DYKDDDDK affinity gels. For use as a control in antibody-peptide competition assays (PCA) use the peptide at 1.0 µg per 1.0 µl of antibody/antiserum in per assay. See anti-DYKDDDDK FLAG® affinity gel PROTOCOL for recommendations for use.