DOSE-DEPENDENT DIELECTROPHORETIC RESPONSE OF CRYPTOSPORIDIUM OOCYSTS TREATED WITH OZONE

Dielectrophoresis, the motion of particles in non-uniform electric fie ld, was investigated as a technology with the potential for rapid anal ysis of ozonated Cryptosporidium parvum oocysts. The ratio of dielectr ophoretic collection at two key frequencies (100 kHz and 10 MHz) was d etermined to compare the effects of ozonation at various dosages. A re lationship was found between this ratio and the in vitro excystation v alue obtained at the end of the experiments. The magnitude of the rati o changed in a non-linear manner with increasing ozone dose. The resul ts are consistent with a decrease in oocyst internal conductivity as s upported by the predictions of a mathematical model for the dielectrop horesis of two-shell spherical particles.