The sporulation of Eimeria tenella as revealed by a novel preparative method

A simple technique for obtaining ultra-thin sections of coccidian oocysts is reported. Oocyst walls, the main barriers to fixatives, dehydrating agents and embedding media are ruptured by brief immersion of the organism in liquid nitrogen. Adequate penetration of chemicals is thus assured but with minimal damage to the internal tissue. The fine structure of sporulation of oocysts of Eimeria tenella was studied using this process. Each oocyst produced four sporoblasts. These developed into sporocysts and each produced two sporozoites.