机构地区: 华南农业大学食品学院
出 处: 《食品科技》 2007年第10期199-202,共4页
摘 要: 研究获得纯化抗志贺氏菌IgY,经检测10mg/mL纯化抗志贺氏菌IgY的效价为1∶320;以志贺氏菌免疫新西兰大耳白兔,获得抗志贺氏菌的兔抗体,效价可达1∶12800。以此两种抗体建立双抗夹心ELISA,正交试验分析表明,兔抗体包被条件为4℃过夜,采用不封闭,抗原与包被抗体结合条件为37℃、1h;加入检测抗体(IgY)的浓度为0.25mg/mL,其结合条件为37℃、1h。该方法对纯培养菌液检出限为105cfu/mL,具有良好的敏感性;10株其他菌株的检测结果表明,该方法只与志贺氏菌发生特异性反应,不与其他菌株的抗原发生交叉反应。染菌的食品样品经选择性增菌后进行双抗夹心ELISA检测,含0.1~1cfu/mL志贺氏菌的样品在增菌13h后可检出阳性反应,含1~10cfu/mL志贺氏菌的样品在增菌11h后可检出阳性反应。 In this paper, anti-Shigella sp. IgY was purified, and the titer of 10mg/mL purified IgY was 1:320. The anti- Shigella sp. IgG was available by injection New Zealand rabbit with Shigella sp. antigen, and the titer was 1:12800. Together with the anti-Shigella sp. IgY and IgG, a double-antibody sandwich enzyme- linked immunosorbent assay (ELISA) was developed with the IgG as the capture antibody and the IgY as the detection antibody. The ELISA conditions were investigated by orthogonal design to select the best one. The detection limits are 10Scfu/mL in pure culture of Shigella sp. and without any cross reaction with the non- Shigella strains. With enrichment procedure, Shigella sp. recovered well from inoculated dehydrated tofu and tap water at two levels of 0.1-lcfu/mL and l-10cfu/mL, the results shew that the double-antibody sandwich ELISA is a sensitive and specific method for detecting Shigella sp. in food samples.