采用大肠杆菌ＤＨ５α菌体蛋白免疫家兔制备抗血清，建立了间接ＥＬＩＳＡ 方法。经初步测定，该方法的灵敏度为０．５ｎｇ／ｍ ｌ，比聚丙烯酰胺凝胶电泳的考马斯亮蓝染色方法的灵敏度高３ ０００倍，比银染色方法的灵敏度高１５０倍。在２０～６２０ｎｇ／ｍ ｌ范围内测定呈直线关系，直线相关系数为０．８９５。经８次重复测定，显示很好的重复性。可用于测定ｒｈＧＭ－ＣＳＦ等基因工程产品中ＤＨ５α菌体蛋白的残余量。 The antiserum was prepared by immunizing rabbits with E. coli DH5α bacterial protein and an indirect ELISA was established. The sensitivity of this method was 0.5ng / ml after preliminary determination, which was 3,000 times higher than the Coomassie blue staining method of polyacrylamide gel electrophoresis and 150 times higher than the sensitivity of silver staining method. In the range of 20 ~ 620ng / m l, there is a linear relationship between the linear correlation coefficient of 0.895. After 8 replicates, showed good repeatability. Can be used to determine the residual amount of DH5α cell protein in genetically engineered products such as rhGM-CSF.