Immunoprecipitation of phospho-tyrosine proteins from A-431 cell extracts, untreated (-) or treated with Human Epidermal Growth Factor (hEGF) #8916 (100 ng/ml, 5 min; +), using Rabbit (DA1E) mAb IgG XP ® Isotype Control (Sepharose ® Bead Conjugate) #3423 (lanes 3 and 4), or Phospho-Tyrosine (P-Tyr-1000) MultiMab™ Rabbit mAb mix (Sepharose ® Bead Conjugate) (Lanes 5 and 6). Western blot analysis was performed using Phospho-Tyrosine (P-Tyr-1000) MultiMab™ Rabbit mAb mix (HRP Conjugate) #12695. Lanes 1 and 2 are 10% input.