Sheather's sucrose solution diluted with distilled water as an alternative to PBS was used to purify oocysts of three different Cryptosporidium spp. The recovery rate of purified Cryptosporidium andersoni, C. baileyi and C. suis oocysts was 47.5%, 49.6% and 41.7%, respectively. The viability of the oocysts was 97.9%, 96.7%, and 95.1%, respectively. After 1 h incubation in a 37 degrees C water bath, the excystation rate of the oocysts was 87.9%, 80.0%, and 81.7%, respectively.