Stains and Staining Methods

Several hematoxylin stains are suitable for staining fecal films containing intestinal protozoa. How a film is prepared, the stain selected, and the staining procedure used will all affect the results and any method for preparing permanently stained slides should be checked out thoroughly before it is put into general use in the laboratory. If in the formalin/polyvinyl alcohol (PVA) system, a wet mount (formalin) and a permanently stained fecal film on every fecal specimen arriving at the laboratory are to be examined, technician time will be increased. After fixation, the fecal film is transferred directly to the first solution of an appropriate staining method and the procedure continued. If staining is done only once each week, probably all solutions, except the stain, should be changed weekly. Otherwise, some of the solutions used in the various staining procedures may be reused for several staining runs, some need to be changed frequently, while others should not be reused.