Improved method for high-yield excystation and purification of infective sporozoites of Eimeria spp

This report describes a new, gentle procedure for rapid and efficient excystation of large numbers of infective sporozoites of Eimeria vermiformis and Eimeria stiedai. Excysted sporozoites are purified using modifications of a previously described ion-exchange chromatography method. The procedure avoids physical breakage of oocysts and results in greater than 70% recovery of the sporozoites present as sporulated oocysts (i.e. 5-6 sporozoites per sporulated oocyst). The recovered sporozoites are greater than 95% pure and are infective in vivo. We routinely isolate greater than 2 x 10(8) sporozoites without the use of specialized or expensive equipment.