以大肠杆菌O157:H7为抗原免疫产蛋母鸡，从鸡卵黄中提取免疫球蛋白，建立抗大肠杆菌O157:H7的特异性IgY的效价检测方法，并研究母鸡的免疫应答性，以及抗体的提取方法和体外抑菌效果。研究结果表明，初次免疫后第6 d，在卵黄中可以检测到抗大肠杆菌O157:H7 IgY，效价为1:7200；经加强免疫后效价迅速上升，至第44 d达到最高效价1:230400；免疫后360 d，效价仍维持在1:7200。用水稀释法、硫酸铵分级盐析和Sephadex G-25凝胶过滤以提取IgY，提纯后IgY的效价是之前的4倍。SDS-PAGE鉴定抗体的纯度，电泳图谱中出现抗体的轻链和重链两条带。体外抑菌实验表明，IgY能抑制大肠杆菌O157:H7的生长。

In this study, the specific IgY was isolated from the yolk of eggs laid by immunized hens with Escherichia coli O157:H7. The methods for the titer detection and isolation of the specific IgY were developed and the inhibitory effects of IgY on the bacteria in vitro were also studied. The results showed that the highest titer of IgY against Escherichia coli O157:H7 was of 1:230400 after 44 days, and still of 1:7200 after 360 days. The titer of the IgY, purified by water dilution, ammonium sulfate precipitation, and gel filtration, was 4 times higher than that of the unpurified. Two major bands were observed in the SDS-PAGE electrophorogram, which represented the heavy and the light chains. The results also demonstrated that the specific IgY could inhibit the growth of Escherichia coli O157:H7.