Histological stains and their application in teaching and research

This review aimed to highlight the historical perspectives focused on histological stains and their application in teaching and research. While early histologists used indigenous substances like alizarin, carmine, and saffron to stain tissues, modern histologists utilize techniques that study cellular organelles and substances within tissues. Despite the advent of new staining techniques, the modification of old ones, and decrease in the use of natural dyes in the 20 th century, some of the stains used in the past are still very much in use. These techniques are used in teaching and research for the demonstration and display of the different substances within tissues. These include the Giemsa stain for parasites and fungi, the Trichrome stain for collagen, oil red O stain for lipids, periodic acid Schiff for glycogen, Crystal violet for Nissl granules, Golgi stain for neuronal cells, as well as routine hematoxylin, and eosin (H&E) for a general histology. Histological stains can be used to teach histology, cellular pathology, microbiology, and parasitology. They can also be used to study the rate of progression of disease or the healing process of diseased conditions