H&E stain

Histologic specimen of human lung tissue stained with hematoxylin and eosin.

H&E stain, HE stain or hematoxylin and eosin stain is a popular staining method in histology. It is the most widely used stain in medical diagnosis; for example when a pathologist looks at a biopsy of a suspected cancer, the histological section is likely to be stained with H&E and termed H&E section, H+E section, or HE section.

The staining method involves application of hemalum, which is a complex formed from aluminium ions and oxidized haematoxylin. This colors nuclei of cells (and a few other objects, such as keratohyalin granules) blue. The nuclear staining is followed by counterstaining with an aqueous or alcoholic solution of eosin Y, which colors other, eosinophilic structures in various shades of red, pink and orange.

The staining of nuclei by hemalum does not require the presence of DNA and is probably due to binding of the dye-metal complex to arginine-rich basic nucleoproteins such as histones. The mechanism is different from that of nuclear staining by basic (cationic) dyes such as thionine or toluidine blue. Staining by basic dyes is prevented by chemical or enzymatic extraction of nucleic acids. Such extractions do not prevent staining of nuclei by hemalum.

The eosinophilic structures are generally composed of intracellular or extracellular protein. The Lewy bodies and Mallory bodies are examples of eosinophilic structures. Most of the cytoplasm is eosinophilic. Red blood cells are stained intensely red.

The structures do not have to be acidic or basic to be called basophilic and eosinophilic. The terminology is based on the affinity to the dyes.

Other colors, e.g. yellow and brown, can be present in the sample; they are caused by intrinsic pigments, e.g. melanin.

Some structures do not stain well. Basal laminae need to be stained by PAS stain or some silver stains, if they have to be well visible. Reticular fibers also require silver stain. Hydrophobic structures also tend to remain clear; these are usually rich in fats, e.g. adipocytes, myelin around neuron axons, and Golgi apparatus membranes.

References

• Godwin Avwioro (2011). Histochemical Uses Of Haematoxylin - A Review. JPCS 1:24-34. PDF
• Kiernan JA (2008) Histological and Histochemical Methods: Theory and Practice. 4th ed. Bloxham, UK: Scion.
• Lillie RD, Pizzolato P, Donaldson PT (1976) Nuclear stains with soluble metachrome mordant lake dyes. The effect of chemical endgroup blocking reactions and the artificial introduction of acid groups into tissues. Histochemistry 49: 23-35.
• Llewellyn BD (2009) Nuclear staining with alum-hematoxylin. Biotech. Histochem. 84: 159-177.
• Puchtler H, Meloan SN, Waldrop FS (1986) Application of current chemical concepts to metal-haematein and -brazilein stains. Histochemistry 85: 353-364.

See also

• Papanicolaou stain, other popular staining technique
• Wright's stain, used for cerebrospinal fluid and suspected lymphomas
• Van Gieson's stain
• Cytopathology
• Staining
• Haematoxylin
• Eosin
• Acid-fast
• Gömöri methenamine silver stain

External links

• SIGMA-ALDRICH H&E Informational Primer
• A video from the American Journal of Medical Videos showing H&E staining steps

Protocol

• Routine Mayer's Hematoxylin and Eosin Stain (H&E)
• Hematoxylin & Eosin (H&E) Staining Protocol
• Rosen Lab, Department of Molecular and Cellular Biology, Baylor College of Medicine) Step by step protocol