Sodium azide used as a preservative for laboratory reagents; a bacteriostatic agent in storage solutions. Inhibits gram negative flora so is therefore included in culture media for the selective isolation of Streptococci and Staphylococci. It has been used to avoid bacterial contamination during RPC-5 column chromatography of DNA fragments.Catalyst for: Oxidative decarboxylation Michael addition reactionsReagent for synthesis of Blue fluorescent copolymers Metal phosphonates Arenes via aminationsInvolved in regioselective synthesis of prianosin B.