Western blot shows lysates of Daudi human Burkitt's lymphoma cell line untreated (-) or treated (+) with 500 U/mL Recombinant Human IFN-a2A (Catalog # 11100-1) 15 minutes, or 100 ng/mL Recombinant Human IFN-? (Catalog # 285-IF) for 15 minutes. PVDF membrane was probed with 1 µg/mL Rabbit Anti-Human Phospho-Jak1 (Y1022/Y1023) Antigen Affinity-purified Polyclonal Antibody (Catalog # AF4510) followed by HRP-conjugated Anti-Rabbit IgG Secondary Antibody (Catalog # HAF008). A specific band for Phospho-Jak1 (Y1022/Y1023) was detected at approximately 130 kDa (as indicated). For additional reference, duplicate lysates were probed with 1.0 µg/mL Human/Mouse/Rat Jak1 Monoclonal Antibody (lower panel, Catalog # MAB4260). This experiment was conducted under reducing conditions and using Immunoblot Buffer Group 3.