Smad1 Antibody Host:Rabbit Antibody Type:Polyclonal Species Reactivity:Human Application:Western blot Western blotting (0.5-4 μg/ml). However, the optimal concentrations should be determined individually. The antibody recognizes ~50-60 kDa Smad1 from samples of human, mouse, and rat origins. Reactivity to other species has not been tested.