Expression and homogeneity of rS100A7 (His-tag) protein. SDS-PAGE 12.5% electrophoresis of rS100A7 (His-tag) protein. The protein was expressed in E. coli BL21::DE3 and purified on an Ni-NTA affinity column. Lanes 1, 2 and 3, are the 1st, 2nd and 3 rd effluents of the column washed with 8 M urea. The gel was stained with Coomassie blue G. Lane 4 is an extract of E. coli which were not transformed (negative control). Lane 5 is a western blot using anti-recombinant S100A7 (His-tag) rabbit serum at 1:5000 dilution. The arrows indicate the electrophoretic position corresponding to rS100A7 (His-tag) protein.