水源水中贾第鞭毛虫和隐孢子虫的滤膜溶解-免疫磁分离-荧光染色检测方法

Membrane dissolution-immunomagnetic separation-immunofluorescence assay for detecting Giardia lamblia and Cryptosporidium in source water

目的建立水源水中贾第鞭毛虫和隐孢子虫的滤膜溶解-免疫磁分离-荧光染色检测方法。方法水样经混合乙酸纤维膜过滤后,溶解于丙酮,离心浓缩,用免疫磁珠分选浓缩产物中的贾第鞭毛虫和隐孢子虫,并用免疫荧光染色剂染色计数。结果贾第鞭毛虫的平均加标回收率为36.58%,分步加标回收率试验中"富集浓缩"这一步加标回收率最低,为57.04%;隐孢子虫的平均加标回收率为19.58%,分步加标回收率试验中"富集浓缩"这一步的加标回收率最低,为26.55%;二者的平均加标回收率均符合我国GB/T 5750—2006《生活饮用水标准检验方法》中回收率高于10%的要求。结论该方法成本低,操作相对简便,适用于普通实验室对水源水中贾第鞭毛虫和隐孢子虫的检测,其中,"富集浓缩"步骤为影响回收率的关键步骤。

Objective To establish a method of membrane dissolution-immunomagnetic separation-immunofluorescence for the detection of Giardia lamblia and Cryptosporidium in source water. Methods The water samples were treated with mixed cellulose ester filter, dissolved in acetone. The mixed cellulose ester in acetone and concentrated by centrifugation;Then used immunomagnetic beads to separate Giardia lamblia and Cryptosporidium in sediment and count by immunofluorescence staining. Results The average recovery rate of standard addition for Giardia lamblia was 36.58%, and the step of concentration had the lowest recovery rate of 57.04% in the examination of the recovery rates of standard addition by step. As for Cryptosporidium, the average recovery rate of standard addition was 19.58%, and also the step of concentration had the lowest recovery rate of 26.55%.The recovery rates of both Giardia lamblia and Cryptosporidium met the requirement of higher than10% in GB 5750-2006. Conclusion With low cost and relative simple, this method is applicable to the determination of Giardia lamblia and Cryptosporidium in source water for a common laboratory. The concentration is the key step that affects the recovery rates.