Hematoxylin (Hematoxylin) and Eosin (Eosin) co-staining referred to as HE staining is one of the most commonly used staining methods in pathology and histology. Hematoxylin is an alkaline natural dye that can color the cell nucleus. The main component of chromatin in the cell nucleus is DNA, and in the double helix structure of DNA, the phosphate groups on the two nucleotide chains are outwardly oriented, which makes the outside of the double helix of DNA negatively charged and acidic, and it can easily be stained by combining with the positively charged Hematoxylin alkaline dye by ionic bonding or hydrogen bonding. The main disadvantage of simple alum hematoxylin cell-nucleus staining is that it is relatively sensitive to any subsequently applied acid dyes, most commonly Van Gieson staining and masson trichrome staining; the acid used in Van Gieson staining removes most of the hematoxylin color to the point that the nucleus is almost invisible, and the use of ferric hematoxylin or asphaltenes blue in such cases resists the effects of the acid and achieves In this case, the use of iron hematoxylin or azurite blue can resist the effect of acid and achieve satisfactory results.

Azurite blue hematoxylin staining solution adopts the combination of azurite blue B and alum hematoxylin, the advantage of which lies in that azurite blue B can resist acid, and high iron salt can strengthen the binding force of alum hematoxylin and cell nucleus to make the cell nucleus staining deeper, so it can achieve the purpose of resisting acid, and make the hematoxylin color not easy to be faded away.