Greater than 90% as determined by SDS-PAGE. ACO1 produced in E.Coli is a single, non-glycosylated polypeptide chain containing 912 amino acids (1-889a.a.) and having a molecular mass of 100.8kDa. ACO1 is fused to a 23 amino acid His-tag at N-terminus & purified by proprietary chromatographic techniques. The ACO1 protein solution (0.5mg/1ml) is formulated in 20mM Tris-HCl buffer (pH8.0) 2mM DTT, 100mM NaCl and 10% glycerol.