Human HSP40(heat shock protein with molecular size of 40kDa) is one of the mammalian homologues of bacterial DnaJ heat shock protein and regulates cellular processes by aiding in the folding, transport and assembly. HSP40 protein contains the J-domain which controls interaction with the ATPase domain of DnaK. Recombinant human HSP40, his-tagged, is overexpressed in E.coli and purified by using the conventional column chromatography techniques.