Basics of H&E staining

• Hematoxylin and Eosin staining is the most common staining technique used in histopathology.
• Displays the underlying tissue morphology with good contrast.

Basic concepts:

Why do dyes stain specific elements of cells and tissue?

• Dyes demonstrate an affinity for molecules within cells and tissue.
• Affinity is the result of attractive forces between dye molecules and molecules within the tissue.

Dye-Tissue interactions are facilitated by Vander Waal's forces, coulombic forces, hydrogen bonding and covalent bonding.

Haematoxylin: It is a basic dye and hence stains the acidic/ basophilic structures.

Nucleus/ nucleoplasm/ organelles that contain RNA - ribosome, ER etc

Eosin: It is an acidic dye and hence stains the basic/ acidophilic structures.

Cytoplasm/ cell wall/ extracellular fibres

In figure, blue staining --> hematoxylin, pink staining --> eosin