Hematoxylin is a reasonably simple stain to make. Hematoxylin is extracted from the logwood tree Hematoxylon campechianum. Hematoxylin has little affinity for tissue on its own. To effectively stain tissue, hematoxylin solutions should contain hematein and a metal mordant (discussed separately in a following section). Oxidation of the hematoxylin produces hematein, a weak dye that is responsible for the staining action in the H&E stain. Addition of the mordant improves the ability of the hematein to attach to the anionic (negatively charged) components of the tissues.
