Ehrlich Hematoxylin Stain

In the staining of cell nuclei, Haematoxylin, which originates from Haematoxylin campechianun, is widely used. The discovery of hematoxylin dates back to 1865 when Bohmer first utilized it for biological sample staining. Over the years, numerous modifications to the original formula have been made, with Mayer introducing a revised version in 1903, followed by many others. Interestingly, even today, staining techniques such as Harris, Gill, Mayer's, and Weigert's are still predominantly employed. Prior to coloring with hematoxylin, it undergoes oxidation facilitated by metal ions, which serve as mordants. Typically, aluminum or iron salts are used as mordants for this purpose.

The nuclear DNA's phosphate group carries a negative charge to which the aluminum-oxyhematoxylin complex is attracted. Staining with hematoxylin produces a blue-purple shade.