Hematoxylin histological staining reagent is suitable for visualization of nuclei in tissue sections and cell preparations. Hematoxylin solutions contain hematein and a metal mordant. The mordant provides the stain color. In the case of Mayer's Hematoxylin (Lillie's modification), the hematoxylin contains aluminum, giving a blue color. Methyl Green enhances nuclear staining in tissue sections and cell preparations when used together with chromogens such as DAB or Fuchsin.