Western Blot Analysis: Untreated (Lane 1) or insulin treated (Lanes 2 and 3) lysates from CHO cells transfected with IR were resolved by electrophoresis, transferred to nitrocellulose, and probed with I7661-22W for 2 hours at RT. Lane 3 was pre-incubated with the blocking peptide immunogen corresponding to phospho-IR (Tyr972). Proteins were visualized via HRP and chemiluminescent detection. Arrow indicates phospho-IR.