Full Description

A vital dye assay was developed in this study to assess the viablility of untreated and ozone treated Cryptosporidium parvum oocysts using a nucleic acid dye, SYTO-9 (Molecular Probes Inc.), and a flow cytometer, FACS (Becton Dickinson). The intensity of oocyst staining by SYTO-9 was evaluated using the flow cytometer with fluorescence histograms, or cytometric profiles, collected for each of the ozone treated and positive control C. parvum oocyst populations. It was found that the difference between the median fluorescence value of a control and ozone treated oocyst population is proportionately related to levels of inactivation as measured by animal infectivity. A linear calibration curve was therefore constructed relating median fluorescence intensity to level of inactivation, expressed in log units. The fitted SYTO-9 calibration model for ozone disinfection of C. parvum oocysts provides a reasonable fit to the animal infectivity assay.

Product Details

Published: 01/01/1998 ISBN(s): 0898679796 Number of Pages: 9