Description: The 5B11 monoclonal antibody reacts with mouse CD123, the alpha chain of the IL-3 receptor. This 60-70 kDa transmembrane protein binds to IL-3 with low affinity by itself and when associated with either CD131 (common beta chain) or AIC2A (IL-3beta) binds IL-3 with high affinity. CD123 does not transduce any intracellular signals upon binding IL-3 and requires the beta chain for this function.