Bukhari Z, McCuin R M, Fricker C R, Clancy J L
Clancy Environmental Consultants, St. Albans, Vermont 05478, USA.
Appl Environ Microbiol. 1998 Nov;64(11):4495-9. doi: 10.1128/AEM.64.11.4495-4499.1998.
Immunomagnetic separation (IMS) procedures which specifically capture Cryptosporidium oocysts and have the potential to isolate oocysts from debris have become commercially available. We compared two IMS kits (kit DB [Dynabeads anti-Cryptosporidium; product no. 730.01; Dynal A.S., Oslo, Norway] and kit IC1 [Crypto Scan IMS; product no. R10; Clearwater Diagnostics Company, LLC, Portland, Maine]) and a modification of kit IC1 (kit IC2 [Crypto Scan IMS; product no. R10; Clearwater Diagnostics Company, LLC]) at three turbidity levels (50, 500, and 5,000 nephelometric turbidity units [ntu]) by using water matrices obtained from different geographical locations. In deionized water, kit DB yielded recoveries between 68 and 83%, whereas the recoveries obtained with kits IC1 and IC2 were more variable and ranged from 0.2 to 74.5%. In water matrices with turbidity levels up to 500 ntu, the oocyst recoveries were more variable with kit DB; however, the recoveries were similar to those obtained in deionized water. In contrast, there were notable reductions in oocyst recoveries in the turbid matrices with kits IC1 and IC2, and the highest recovery (8.3%) was obtained with a 50-ntu sample. An examination of the effects of age on oocyst recovery with kit DB revealed that oocysts up to 16 weeks old yielded recoveries similar to the recoveries observed with fresh oocysts. These data indicate that all IMS kits do not perform equally well, and it is important to conduct in-house quality assurance work before a commercially available IMS kit is selected to replace flotation procedures for recovery of Cryptosporidium oocysts.
能够特异性捕获隐孢子虫卵囊并有可能从碎片中分离出卵囊的免疫磁分离（IMS）程序已实现商业化。我们比较了两种IMS试剂盒（试剂盒DB [抗隐孢子虫磁珠；产品编号730.01；挪威奥斯陆的Dynal A.S.公司]和试剂盒IC1 [隐孢子虫扫描免疫磁分离试剂盒；产品编号R10；缅因州波特兰的清水诊断公司有限责任公司]）以及试剂盒IC1的一种改良版本（试剂盒IC2 [隐孢子虫扫描免疫磁分离试剂盒；产品编号R10；清水诊断公司有限责任公司]），使用从不同地理位置获取的水基质，在三种浊度水平（50、500和5000散射浊度单位[ntu]）下进行比较。在去离子水中，试剂盒DB的回收率在68%至83%之间，而试剂盒IC1和IC2的回收率变化更大，范围为0.2%至74.5%。在浊度高达500 ntu的水基质中，试剂盒DB的卵囊回收率变化更大；然而，回收率与在去离子水中获得的回收率相似。相比之下，试剂盒IC1和IC2在浑浊基质中的卵囊回收率显著降低，50 ntu样品的最高回收率为8.3%。对试剂盒DB中卵囊回收率的年龄影响进行检查发现，16周龄以下的卵囊回收率与新鲜卵囊的回收率相似。这些数据表明，并非所有的IMS试剂盒都具有同等良好的性能，在选择商业化的IMS试剂盒来替代浮选程序以回收隐孢子虫卵囊之前，进行内部质量保证工作非常重要。
