RAB1B is a member of the RAB protein family, low molecular mass monomeric GTPases localized on the cytoplasmic surfaces of distinct membrane bound organelles. This protein functions in the early secretory pathway and is essential for vesicle transport between the endoplasmic reticulum (ER) and Golgi. Recombinant human RAB1B protein, fused to His-tag at N-terminus, was expressed in E.coli and purified by using conventional chromatography.