MODIFIED IRON HEMATOXYLIN STAIN: Procedure Notes (cont.)

1. The first 70% alcohol step acts with the Mayer's albumin to ``glue'' the specimen to the glass slide. The specimen may wash off if insufficient albumin is used or if the slides are not completely dry prior to staining.

2. The working hematoxylin stain should be checked each day of use by adding a drop of stain to alkaline tap water. If a blue color does not develop, prepare fresh working stain solution.

3. The picric acid differentiates the hematoxylin stain by removing more stain from fecal debris than from the protozoa and removing more stain from the organism cytoplasm than from the nucleus. When properly stained, the background should be various shades of gray-blue and protozoa should be easily seen with medium blue cytoplasm and dark blue-black nuclei.