aluminumhematoxylin

Aluminumhematoxylin is a histochemical stain used in the preparation of tissue sections for light microscopy. It consists of hematoxylin, a basic dye extracted from the logwood tree (Haematoxylum campechianum), complexed with aluminum ions, usually supplied as aluminum nitrate or aluminum chloride. The combination enhances the dye’s affinity for nucleic acids and significantly improves the staining of acidic cellular components such as DNA and RNA, rendering nuclei a distinctive purple or blue hue.

The staining procedure typically begins with deparaffinisation and rehydration of paraffin‑embedded tissue sections. The sections are then immersed in the aluminumhematoxylin solution, which is often boiled to dissociate hematoxylin crystals and to promote uniform aluminum complexation. After rinsing, the tissue is counterstained with eosin, which dyes cytoplasmic and extracellular matrix structures in varying shades of pink. A final dehydration and mounting step completes the preparation. The resulting contrasting colors allow pathologists to readily distinguish cell nuclei from the surrounding cytoplasm and connective tissue.

Compared with conventional hematoxylin, aluminumhematoxylin offers faster staining times and reduced tissue background. It also increases staining stability, permitting longer shelf life of prepared slides. However, the use of aluminum salts may pose environmental and disposal concerns, and the pigment can occasionally produce faint red‑brown artefacts if staining time is not carefully controlled. Modern variations, such as Mayer’s or Gill’s hematoxylin, achieve similar results with alternative mordants, but aluminumhematoxylin remains popular in many routine histology laboratories worldwide due to its robust performance and simplicity of preparation.