What are the pros and cons of using stool fixatives?
Although it would be helpful to see motile organisms in the direct saline wet preparation, often the trophozoite forms have already begun to disintegrate by the time the stool specimen reaches the laboratory. In order to reduce the lag time between passage of the specimen and submission/arrival in the laboratory, stool fixatives are recommended. The benefits of fixation and preservation of organism morphology far outweigh the benefits of receiving a fresh, unpreserved stool.