A technique for obtaining thin sections of coccidian oocysts.

A double sectioning technique is described for obtaining thin sections of coccidian oocysts. This method employs cryostat sectioning of unfixed oocysts prior to treatment by normal methods of fixation, dehydration, embedding and thin sectioning for electron microscopy. A number of the oocysts treated by this technique were well preserved anc contained organelles with normal ultrastructure.