为了改善水中隐孢子虫卵囊的监测，美国 环境保护局开发了1622方法，包括过滤， 浓度、免疫磁分离、荧光抗体和4,6-二氨基-2-苯基吲哚 （DAPI）反染色和显微镜评估。对两个过滤器进行了比较 对美国各地收集的11个溪水样本进行分析。 复制10-L溪水样本（未标记并添加100-250个卵囊） 进行测试以评估基质效应。从溪水样本中回收卵囊 膜盘平均22%（标准偏差[SD]=+/-17%）和12% （SD=+/-19%）带有胶囊过滤器。这些结果表明隐孢子虫 使用1622方法可以从溪水中回收卵囊，但回收率很低 低于试剂级水。这项研究还评估了浓度 溪水样本中指示细菌的数量。因为很少有样本是卵囊阳性的， 卵囊检测与指示生物浓度的关系 无法确定。包括28个参考文献和表格。

To improve surveillance for Cryptosporidium oocysts in water, the US Environmental Protection Agency developed method 1622, which consists of filtration, concentration, immunomagnetic separation, fluorescent antibody and 4,6-diamidino-2-phenylindole (DAPI) counter-staining, and microscopic evaluation. Two filters were compared for analysis of 11 stream water samples collected throughout the United States. Replicate 10-L stream water samples (unspiked and spiked with 100-250 oocysts) were tested to evaluate matrix effects. Oocyst recoveries from the stream water samples averaged 22% (standard deviation [SD] =+/-17%) with a membrane disk and 12% (SD=+/-19%) with a capsule filter. These results demonstrate that Cryptosporidium oocysts can be recovered from stream waters using method 1622, but recoveries are lower than those from reagent-grade water. This research also evaluated concentrations of indicator bacteria in the stream water samples. Because few samples were oocyst-positive, relationships between detections of oocysts and concentrations of indicator organisms could not be determined. Includes 28 references, tables.