HæmatoxylinEosin

Hämatoxylin-Eosin staining, commonly abbreviated as H&E, is the standard stain used in histology and surgical pathology to reveal tissue architecture. Hematoxylin stains nuclei and other basophilic structures a blue to purple color, while eosin counterstains cytoplasm, collagen, and other eosinophilic components pink. The combination provides contrast that helps distinguish cell types, tissue organization, and pathological changes.

Hematoxylin is typically used with a mordant to form a colored complex that binds to nucleic acids; the precise shade is influenced by the oxidation state and the use of alkaline blueing steps. Eosin is an acidic dye that binds to basic, protein-rich structures in the cytoplasm and extracellular matrix. In routine protocols, fixed tissue is embedded in paraffin, sectioned, deparaffinized, and subjected to hematoxylin staining for several minutes, followed by differentiation and blueing to intensify nuclear staining. A brief eosin counterstain is then applied, after which slides are dehydrated and mounted for microscopic examination.

A widely used, general-purpose stain, H&E is employed to assess tissue morphology in diagnosis and research. It is not specific for particular molecules, so it is often complemented by specialized stains or immunohistochemistry when finer differentiation is needed. Variants of hematoxylin (such as Harris or Mayer’s) and adjustments in pH and duration influence stain intensity and contrast. Proper technique minimizes artifacts and fading and ensures reliable evaluation of cellular and architectural details.