BSND is an essential beta subunit for CLC chloride channels. These heteromeric channels localize to basolateral membranes of renal tubules and of potassium-secreting epithelia of the inner ear. Mutations in this BSND have been associated with Bartter syndrome with sensorineural deafness. Recombinant human BSND protein, fused to His-tag at N-terminus, was expressed in E.coli and purified by using conventional chromatography techniques.