Sigmoidoscopic Material

Biopsy material for amebiasis should be processed for surgical pathology and then examined for ulcers containing amebae. The periodic acid-Schiff stain counterstained with hematoxylin is particularly helpful because amebae stain more positively with periodic acid-Schiff stain than do inflammatory cells, and amebae show typical amebic nuclei. Of course, there are no amebic cysts in tissue. 

Biopsy material for schistosomiasis is better examined in teased preparations than in sections, as the entire thickness can be examined at once, and the viability of eggs can be determined by observation of the movement of the larvae within the eggs. 

In cryptosporidiosis, biopsy material shows organisms at the luminal surface of the epithelial cells, but the organisms are small, and the study of structural detail requires electron microscopy. 

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Free-living amebae Sigmoidoscopic material Fix films in Schaudinn fixative or mix material with PVA fixative. 

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