The NK1R antiserum was quality control tested using standard immunohistochemical methods in rat brain using biotin/avidin-HRP techniques. Specificity of the antiserum was demonstrated by soluble pre-adsorption and Western blot. Tissue staining is completely eliminated by pretreatment of the diluted antibody with 10 mg of rat NK1R peptide residues 393-407. Western blot analysis demonstrates two immunoreactive bands of approximately 70 and 110 kD.