Tryptophan hydroxylase, mAb (WH-S) Tryptophan hydroxylase is regarded as the rate-limiting enzyme in serotonin (5-HT; 5-hydroxytryptamine) biosynthesis. TPH immunoreactivity is localised exclusively to serotonergic neurons in the central and peripheral nervous systems. Product Specification Clone: WH-S Host: Mouse Isotype: IgG3 Immunogen: Recombinant rabbit tryptophan hydroxylase. Application: Immunohistochemistry Western Blot Specificity: Recognizes primate, rabbit, rat and cat tryptophan hydroxylase. Formulation: Liquid. Ascites containing 0.1% sodium azide. Long Term Storage: -20°C