食品科学 ›› 2007, Vol. 28 ›› Issue (1): 171-175.

• 生物工程 • 上一篇    下一篇

双抗夹心ELISA检测食品中大肠杆菌O157:H7方法研究

 葛萃萃, 钟青萍, 张旺, 欧阳鑫   

  1. 华南农业大学食品学院; 华南农业大学食品学院 广东广州510640; 广东广州510640;
  • 出版日期:2007-01-15 发布日期:2011-12-31

Study on Double-antibody Sandwich ELISA for Detecting E.coli O157 in Food

 GE  Cui-Cui, ZHONG  Qing-Ping, ZHANG  Wang, 欧Yang-Xin   

  1. College of Food Science, South China Agricultural University, Guangzhou 510640, China
  • Online:2007-01-15 Published:2011-12-31

摘要: 研究获得纯化抗大肠杆菌O157:H7IgY抗体,经检测10mg/ml纯化IgY抗体的效价为1:320;以大肠杆菌O157:H7免疫新西兰大耳白兔,获得兔抗大肠杆菌O157:H7IgG抗体,效价达1:25600。以兔抗大肠杆菌O157:H7IgG抗体稀释3200倍作为捕获抗体,抗大肠杆菌O157:H7IgY抗体为检测抗体建立双抗夹心ELISA方法检测大肠杆菌O157:H7,正交试验分析表明,捕获抗体于37℃包被2h、不封闭、抗原与捕获抗体于37℃结合2h、检测抗体浓度为0.25mg/ml、与抗原于37℃结合1h为最优反应条件。该方法对纯培养菌液检出限为105CFU/ml,具有良好的敏感性及特异性。染菌样品经在EC增菌液中选择性培养后进行双抗夹心ELISA检测,接种量为0.1~1CFU/g(ml)的样品在培养12h后可检出阳性反应,1~10CFU/g(ml)的样品在培养8h后可检出阳性反应。

关键词: 大肠杆菌O157:H7, 双抗夹心ELISA, 检测

Abstract: In this paper, anti-E.coli O157:H7 IgY was purified, and the titer of 10mg/ml purified IgY was 1:320. The anti- E.coli O157:H7 IgG was available by injection New Zealand rabbit with E.coli O157:H7 antigen, and the titer was 1:25600.Together with the IgY and IgG specific to E. coli O157, a double-antibody sandwich-ELISA was developed with IgG diluted 3200 fold as the capture antibody, and IgY as the detection antibody. Besides, the results of cross-experimentation of sandwich-ELISA described: ① IgG coating in 37℃ for 2h, ② reaction of IgG with antigen in 37℃ for 2h, and ③ concentration of IgY as 0.25mg/ml, and reaction of IgY with antigen in 37℃ for 1h. The detection limit of this method is 105CFU/ml, and has no cross reactions with other bacteria. With enrichment procedure in 41℃ and 200 r/min, E. coli O157:H7 recovers well from inoculated food samples. The results showed that the samples are detected after being cultured 12h at 0.1~1CFU/g(ml) and 8h at 1~ 10CFU/g(ml) respectively.

Key words: E. coli O157, double-antibody sandwich ELISA(enzyme linked immunosorbent assay), detect