To produce the monoclone antibodies to the human early pregnancy factor (EPF), BALB/C mice were immunized with EPF.

• 用纯化的早孕因子(EPF)免疫BALB/C小鼠,取其脾脏与SP2/0小鼠骨髓瘤细胞融合,用酶联免疫吸附试验(ELISA)间接法筛选,以有限稀释法进行克隆化。