One of the steps in the H&E staining procedure is bluing. As the name implies, this step converts the initial soluble red color of the hematoxylin within the nucleus to an insoluble blue color. The alkaline pH of the bluing solution causes the mordant dye-lake to reform in the tissue and become more permanent. Some examples of bluing solutions include:
- Ammonia water
- Dilute lithium carbonate
- Scott's tap water (potassium carbonate, magnesium sulfate, and water)
