检测大肠杆菌菌体蛋白的夹心ELISA试剂盒的建立及应用研究

目的  建立特异、敏感的检测大肠杆菌菌体蛋白的夹心ELISA试剂盒。方法  采用大肠杆菌菌体蛋白免疫家兔，制备得到高效价抗菌体蛋白抗血清。将经饱和硫酸铵盐析、阴离子交换柱层析和亲和层析纯化的兔抗大肠杆菌菌体蛋白特异性多克隆抗体作为包被抗体和检测抗体，用生物素标记检测抗体，并加入辣根过氧化物酶（HRP）标记的亲和素。结果　建立的大肠杆菌菌体蛋白夹心ELISA检测方法的敏感性为0.32 μg/L，检测范围为1~100 μg/L，与国际同类商品化试剂盒相当。此法具有良好的稳定性，其批内变异系数小于7.7%，批间变异系数小于6.2%。结论  建立了特异、敏感、稳定的检测大肠杆菌菌体蛋白的夹心ELISA试剂盒，为生物制品中残留大肠杆菌菌体蛋白的质量控制提供了一种重要的检测方法。

Establishment and application of sandwich ELISA kit for detection of E. coli cell proteins

Objective To establish a highly specific and sensitive sandwich ELISA kit for detection of E. coli cell proteins. Methods E. coli cell proteins were used for immunization of rabbits and high titer antisera were obtained. The polyclonal antibodies(PAbs)against E. coli cell proteins were purified by saturated ammonium sulfate salting-out, anion exchange chromatography and affinity chromatography. The purified PAbs were used as coating antibodies, and biotin-labeled PAbs plus horseradish peroxidase-conjugated avidin were used as detecting antibodies. Results The sensitivity and detection range of the sandwich ELISA system for detection of E. coli cell proteins were 0.32 μg/L and 1-100 μg/L, respectively, and equal to the similar commercial kits in the world. This ELISA kit had good stability, and its intra- and inter-assay variation coefficients were less than 7.7% and less than 6. 2%, respectively. Conclusions The sandwich ELISA kit with high specificity, sensitivity and stability is established successfully and provides an important method for quality control of residual E. coli cell proteins in biological products.