Evaluation of rcaIL-2 expression and affinity purification by SDS-PAGE and Western blot. A. Samples analysed in 15% polyacrilamide gel stained with Commassie blue. Lane 1, Molecular weight markers; Lane 2, E. coli BL21(DE3)pLysS-pRSET without insert; Lane 3, BL21(DE3)pLysS-pRSET-caIL-2; Lane 4, affinity purified rcaIL-2-F43L. B. Samples evaluated by Western blot developed with an anti-His tag monoclonal antibody conjugated with alkaline phosphatase. Lane 1, E. coli BL21(DE3)pLysS-pRSET without insert; Lane 2, BL21(DE3)pLysS-pRSET-caIL-2; Lane 3, affinity purified rcaIL-2-F43L; and Lane 4, affinity purified His-tagged enhanced green fluorescent protein (EGFP, positive control). Arrows and arrow head indicate rcaIL-2F43L and EGFP bands, respectively.