12.5% SDS-PAGE of C-His-Rv2135c expressed in E. coli BL21(DE3) with or without induction and its purified form. Lane 1: 5 μl of 10–250 kDa protein ladder (New England Biolabs). Lane 2: 10 μg of crude lysate of E. coli BL21(DE3) without any plasmid. Lane 3: 8.5 μg of crude lysate of E. coli BL21(DE3)-35c before induction with IPTG. Lane 4: 30 μg of crude lysate of BL21(DE3)-35c after induction with 0.4 mM IPTG for 8 hours at 25°C. Lane 5: 4 μg of recombinant C-His-Rv2135c eluted from IMAC column.