Chemical basis of staining.
The most widely used histological stains differentiate between the acidic and basic components of cells and tissues.
Basic dyes have a net positive charge and bind to components of cells and tissues that are negatively charged.
Tissue components that stain with basic dyes are referred to as basophilic.
Acidic dyes have a net negative charge and bind to components of cells and tissues that are positively charged.
Tissue components that stain with acid dyes are referred to as acidophilic.
Hematoxylin and eosin (or H&E) is the most commonly used stain in histology. This stain works well with a variety of fixatives and stains a broad range of cytoplasmic, nuclear, and extracellular matrix features.
Hydrophobic structures (such as those rich in fats) do not stain well with H&E.