Description_x000D_ Application_x000D_ Aurintricarboxylic acid ammonium salt has been used as a nuclease inhibitor to study its effects on transfection._x000D_ Packaging_x000D_ 25 g in glass bottle_x000D_ Biochem/physiol Actions_x000D_ Aurintricarboxylic acid readily polymerizes in aqueous solution, forming a stable free radical that inhibits protein-nucleic acid interactions. It is a potent inhibitor of ribonuclease and topoisomerase II by preventing the binding of the nucleic acid to the enzyme. It stimulates tyrosine phosphorylation processes including the Jak2/STAT5 pathway in NB2 lymphoma cells, ErbB4 in neuroblastoma cells, and MAP kinases, Shc proteins, phosphatidylinositide 3-kinase and phospholipase C in PC12 cells. Aurintricarboxylic acid inhibits apoptosis in many cell types. Its neuroprotective effect, perhaps due to its ability to prevent down-regulation of Ca2+ impermeable GluR2 receptors or to its ability to inhibit calpain, a Ca2+-activated protease that is activated during apoptosis._x000D_ Other Notes_x000D_ May contain a substantial amount of polymeric material.