Methods Expression vector pCTLA 4/Ig was transfected into COS 7 with lipid reagent. The expression of fusion protein in the supernatant of the cell culture media was detected with double antibody sandwich ELISA.

• 方法 将pCTLA 4/Ig表达质粒转染COS 7细胞 ,双抗体夹心ELISA检测细胞培养上清中融合蛋白表达 ;