SDS-PAGE determination of purified prokaryotic expression protein pET28a-UGT84A77. M, protein marker; lane 1 indicates protein expression not induced by IPTG; lane 2 indicates total protein induced by IPTG; lane 3 indicates total soluble protein in supernatant; lane 4 indicates insoluble protein in pellet; lane 5 indicates effluent after flowing through resin; lane 6 indicates washing buffer after flowing through resin; lanes 7–15 indicate the proteins eluted by 40, 60, 80, 100, 120, 140, 160, 180, and 200 mM imidazole eluents, respectively; the underline indicates the purified objective protein of pET28a-UGT84A77.