SRY (sex determining region Y)-box 2, also known as SOX2, is a transcription factor that is essential to maintain self-renewal of undifferentiated embryonic stem cells. This Protein is a member of the SRY-related HMG-box (SOX) family of transcription factors involved in the regulation of embryonic development and in the determination of cell fate. The product of this gene is required for stem-cell maintenance in the central nervous system, and also regulates gene expression in the stomach. Recombinant human SOX2 protein was expressed in E.coli and purified by using conventional chromatography techniques.