Description General description Spermidine is a polyamine and a trivalent organic cation. Application Spermidine trihydrochloride has been used as standard for the detection of biogenic amines using HPLC. Biochem/physiol Actions Inhibits neuronal nitric oxide synthase (nNOS). Binds and precipitates DNA; may be used for purification of DNA binding proteins. Stimulates T4 polynucleotide kinase activity. Spermidine modulates various cellular activities like cellular development and differentiation, stability of DNA and apoptosis. Caution Solutions should be sterile-filtered, not autoclaved, if sterile solution is necessary. Spermidine deaminates with time; solutions should be stored frozen. Prepare new solutions frequently.