Anti-EGFR (phospho Y869) Antibody

Raised in rabbit against a synthetic phospho-peptide corresponding to the activation loop of human EGFR, this polyclonal IgG reagent from Antibodies.com selectively recognizes the receptor only when tyrosine 869 is phosphorylated. Y869 is functionally distinct from the canonical C-terminal autophosphorylation sites Y1068, Y1086 and Y1173: it lies in the kinase domain next to the L858 and L861 hotspots mutated in non-small-cell lung cancer, does not itself drive EGFR catalytic activity, and instead acts as a docking site for the SH2 domain of STAT5 to feed mitogenic and survival signaling. The unconjugated, affinity-purified reagent is supplied as 100 µl of liquid in PBS (pH 7.4) with 150 mM NaCl, 50% glycerol and 0.02% sodium azide, and on Western Blot of human cell lysates detects the mature 134 kDa EGFR band with HRP-conjugated secondary antibodies and chemiluminescent readout. Because the phospho-epitope is sensitive to dephosphorylation and repeated freeze-thaw, aliquot the vial on receipt and store at -20 °C; thaw only what is needed for each experiment. The antibody is reactive with human EGFR and is intended for research use only, making it a useful complement to total-EGFR and C-terminal phospho-site antibodies when dissecting receptor activation dynamics.