Akr1b1, also known as Aldose reductas, is an enzyme. It catalyzes the NADPH-dependent reduction of a wide variety of carbonyl-containing compounds to their corresponding alcohols with a broad range of catalytic efficiencies. Recombinant mouse Akr1b1, fused to His-tag at N-terminus, was expressed in E.coli and purified by using conventional chromatography techniques.