A simple staining technique to demonstrate the sporozoite refractile globule in coccidian parasites

A staining technique was developed for locating the sporozoites of Eimeria spp. in both mammalian and avian hosts. Bouin-fixed tissues embedded in Paraffin wax and cut at a thickness of 3 micrometers were stained by a controlled sequence of Ehrlich's haematoxylin, acid fuchsin and aniline blue-orange G-acetic acid which took only 30 min to perform. The refractible globule of the sporozoite stained a brilliant crimson whilst the tissue had an overall blue colour, thus enabling rapid scanning of material under low-power magnification. The granules of eosinophils and heterophils also stained a brilliant crimson and their significance in immunological responses indicates a wider application for this technique.