This antiserum was produced against canine cardiac sarcolemmal Na+ -Ca2+ exchanger (NCX1; full length isolated protein). The specific epitope was never mapped, but is likely to be primarily on the large intracellular loop. Brain, smooth muscle and kidney Na+ -Ca2+ exchanger are also recognized by the antiserum. The antiserum cross reacts with the proteins of mouse, rat, rabbit, frog, toad, guinea pig, cow and human. It does not react with NCX2 or NCX3. The antiserum can be used for immunoblots, immunoprecipitation and immunohistochemistry.