thumb|300px|[[Blood film with Giemsa stain. Monocytes surrounded by erythrocytes.]]
Romanowsky staining is a prototypical staining technique that was the forerunner of several distinct but similar stains widely used in hematology (the study of blood) and cytopathology (the study of diseased cells). Romanowsky-type stains are used to differentiate cells for microscopic examination in pathological specimens, especially blood and bone marrow films, Other methods have been employed, as well, such as oxidation in acidic medium with dichromate anion.
Although azure B and eosin have been shown to be the required components to produce the Romanowsky effect, -->
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