Greater than 90.0% as determined by SDS-PAGE. POLB Human Recombinant produced in E.Coli is a single, non-glycosylated polypeptide chain containing 355 amino acids (1-335 a.a) and having a molecular mass of 40.3kDa. POLB is fused to a 20 amino acid His-tag at N-terminus; purified by proprietary chromatographic techniques. POLB protein solution (0.5mg/ml) containing 20mM Tris-HCl buffer (pH 8.0), 1mM DTT, 30% glycerol and 0.1M NaCl.