结果成功引入点突变并构建置换型打靶载体，转染es细胞后经药物筛选得到抗性细胞克隆。
The drug resistant cell clones were picked after drug selection. Results The construction of targeting vectors was successful and several drug resistant es cell clones were gained.
针对海藻酸钠载体强度低、易分解的缺点，采用添加法和置换法对载体进行改性研究，并确定了最佳固定化条件。
Two different methods, addition and displacement were adopted so as to improve the strength of calcium-alginate beads, and the best immobilized condition was adopted.
应用推荐