Purity >95% by SDS-PAGE. DHFR?Mouse Recombinant fused with a?20 amino acid His tag at N-terminus produced in E.Coli is a single, non-glycosylated, polypeptide chain containing?207 amino acids (1-187 a.a.) and having a molecular mass of 23.8kDa. The DHFR is purified by proprietary chromatographic techniques.