Purity: > 90% by SDS - PAGE Format: Liquid. In 20 mM Tris-HCl buffer (pH8.0) containing 0.2M NaCl, 2mM DTT, 10% glycerol . APEX1, also known as REF1 or APE1 (Apurinic / apyrimidinic endonuclease), is responsible for the incision of DNA basic sites during base excision repair. It has also been shown to stimulate the DNA binding activity of numerous transcription factors that are involved in cancer promotion and progression. APEX1 is part of the cellular response to oxidative stress and protects cells from the genotoxic and cytotoxic effect of oxidizing agents. Recombinant human APEX1 protein, fused to T7-tag at N-terminus, was expressed in E.coli and purified by using conventional chromatography techniques.