Western blot using RRM2B polyclonal antibody (Cat # PAB16911) shows detection of recombinant (Lanes 1 and 3) and endogenous protein (Lanes 1 to 4) in whole cell extracts from transfected 293T. Lane 1 contains purified recombinant human p53R2. Lane 2 contains 293T cells transfected with control vector. Lane 3 contains 293T transfected with p53R2-myc. Lane 4 : 293T transfected with ScRNA. Lane 5 : 293T tranfected with p53R2 SiRNA The band at 40.7 KDa, indicated by the bottom arrowhead, corresponds to the expected molecular weight of endogenous RRM2B. The band with the middle arrow corresponds to myc-tagged p53R2 at 41.9 KDa. The highest band at 44.3 KDa corresponds to recombinant p53R2. Primary antibody was diluted to 1 ug/mL and incubated overnight at 4°C. ECL detection was used.