The primary goal of histological staining methods is to visualise various cellular and tissue structures in formalin-fixed, paraffin-embedded samples. These methods leverage the differing affinities of dyes for specific tissue components to identify basophilic, acidophilic, or neutrophilic structures. Basophilic elements, such as cell nuclei, are stained with basic dyes, while acidophilic structures are highlighted using acidic dyes. Since most dyes are aqueous solutions, tissue preparations must be deparaffinised before staining. The process involves hydrating the tissue through a graded alcohol series, applying the stain, and preserving the sample for long-term storage through dehydration and the use of a mounting medium.

The hematoxylin-eosin (HE) stain is the most widely used routine stain in histology, ideal for revealing intricate tissue structures. Hematoxylin, a natural dye, binds to cell nuclei, while the acidic dye eosin stains all acidophilic components like cytoplasm and plasma proteins.

Additional key histological staining techniques are summarized in the table below.