Routine H&E staining and special stains play a critical role in tissue-based diagnosis or research. By colouring otherwise transparent tissue sections, these stains allow highly trained pathologists and researchers to view under a microscope the tissue morphology (structure) or to look for the presence or prevalence of particular cell types, structures or even microorganisms such as bacteria.

In the histopathology laboratory, the term “routine staining” refers to the hematoxylin and eosin stain (H&E) that is used “routinely” with all tissue specimens to reveal the underlying tissue structures and conditions. The term “special stains” has long been used to refer to a large number of alternative staining techniques that are used when the H&E does not provide all the information the pathologist or researcher needs.