Western Blot Analysis of Cell Signaling

Protein samples were electrophoresed using 7.5 or 10% SDS–PAGE and performed as previously described [45 (link)]. Membranes were incubated with the primary antibodies against pEGFR Y1173 (Cell Signaling, #4407), EGFR (Transduction Laboratories, E12020), pHER2 Y1248 (Cell signaling, #2247), HER2 (Millipore, #06-562), pHER3 Y1289 (Cell signaling, #4791), HER3 (Millipore, #05-390), pERK1/2 (Cell Signaling, #9101), ERK1 K23 (Santa Cruz, sc-94), pAKT (Cell Signaling, #9271), AKT1/2/3 H-136 (Santa Cruz, sc-8312), PARP (Cell Signaling, #9542), Tubulin (Sigma, T9026), Secondary HRP-conjugated anti-rabbit (Bio-Rad) and anti-mouse (Sigma) antibodies were used and detection was done using an ECL reagent.