Detection of flow-sorted C. parvum oocysts in environmental samples1.

10.5 ml packed pellets from raw surface water were processed through the IMS procedure of USEPA Method 1622 and were spiked with flow-sorted C. parvum oocysts to determine detection limits of Cryptosporidium spp. and C. parvum specific qPCR assays on environmental samples. Results are the average CT values of three independent experiments ± standard deviation. Triplicate reactions were performed for each condition tested in each of the three experiments conducted.2CT values ± standard deviation. Numbers in parentheses are the ratio of positive qPCR reactions over the total reactions performed.3“Mock” flow-sorted sample containing no oocysts, environmental sample present.4the CRU18S pan-Cryptosporidium spp. cross reacted with indigenous non-Cryptosporidium oocyst present in the environmental sample.5Unspiked, sample containing no oocysts and no environmental sample.*, Not detected (CT>40).