双抗体夹心ELISA法测定食物中牛奶过敏原蛋白成分

Detection of milk allergen protein trace in food products by sandwich-antibody enzyme linked immunosorbent assay

建立双抗体夹心酶联免疫吸附测定法(ELISA)测定食物中牛奶过敏原成分。通过提取牛奶过敏原蛋白,免疫小鼠制备抗牛奶过敏原的多抗,免疫印迹法鉴定多抗与牛奶过敏原蛋白的反应,并建立双多抗夹心ELISA法。结果表明,该法检测牛奶过敏原蛋白的最低检出限为25μg/L,标准曲线在25～1000μg/L范围内线性良好;同时对市场上食物标签标注含有牛奶、未含牛奶成分以及标注不详共12种食品进行检测,结果10种食品检测结果与食物标签标注内容相符,而2种标示不详的食品检测结果一个呈现阳性,一个呈现阴性。这说明本方法对于未标注牛奶过敏原成份的食品检测具有一定的实际应用价值。

Here we report a new method that sandwich-antibody enzyme linked immunosorbent assay （ELISA） was successfully used to detect milk allergen protein in food products. The Balb/c mice were immuned with the extracts of milk allergen proteins and the highly-titrated polyclonal IgG antibodies against them were isolated for our immunoblotting assay. The total milk allergen protein was extracted and further analyzed by SDS-PAGE. Our results indicated that the standard curve is linear with milk allergen protein concentration from 25 to 1000 ng/ mL, and the detection limit is 25 ng/mL of milk allergen protein. Food products from markets were tested using this method. We found that 10 foods were detected with the milk allergen protein, which were consistent with the food allergen labels from their manufactures. However, one food without food allergen label was detected to contain milk allergen protein and the other one without food allergen label was tested to contain no milk allergen protein. Thus we concluded that sandwich-antibody ELISA could be used to detect milk allergen in food products. .