Western blot analysis of Strep-Tag II on different lysates. Proteins were transferred to a PVDF membrane and blocked with 5% BSA in PBS for 1 hour at room temperature. Strep Tag II Polyclonal Antibody (Product # PA5-119772) at 1:40,000 was used in 5% BSA at room temperature for 2 hours. Goat Anti-Rabbit IgG - HRP Secondary Antibody at 1:5,000 dilution was used for 1 hour at room temperature. Positive control: Lane 1: Strep-Tag II protein transfected 293F cells lysate. Lane 2: Non-transfected 293F cells lysate.