Romanowsky stain
The value of Romanowsky staining lies in its ability to produce a wide range of hues, allowing cellular components to be easily differentiated.
[7] Eosin part of the stain is responsible for pink-orange hue of erythrocytes and granules inside cytoplasms of eosinophilic leukocytes.
In 1891 Romanowsky[8][9][10] developed a stain using a mixture of eosin (typically eosin Y) and aged solutions of methylene blue that formed hues unattributable to the staining components alone: distinctive shades of purple in the chromatin of the cell nucleus and within granules in the cytoplasm of some leukocytes.
[15] Common method of rapid oxidation uses increasing pH of the solution with potassium carbonate and boiling it, which introduces atmospheric oxygen.
[4] The addition of Giemsa to Wright's stain increases the brightness of the "reddish-purple" color of the cytoplasmic granules.
Giemsa stain is composed of "Azure II" and eosin Y with methanol and glycerol as the solvent.
[5] The May-Grünwald-Giemsa is used for the staining of slides obtained by fine-needle aspiration in a histopathology lab for the diagnosis of tumorous cells.
[24] Although debate exists as to who deserves credit for this general staining method, popular usage has attributed it to Dmitri Leonidovich Romanowsky.
[25][26][27][28][17] In 1888 Cheslav Ivanovich Chenzinsky used methylene blue, but substituted the acid fuchsin used by Ehrlich with eosin.
[19] In 1899, Louis Leopold Jenner developed a more stable version of the methylene blue and eosin stain by collecting the precipitate that forms in water-based mixtures and redissolving it in methanol.
[28][19][15] In 1901, both Karl Reuter and William Leishman[22] developed stains that combined Louis Jenner's use of alcohol as the solvent and Malachowsky's use of polychromed methylene blue.
[19][4] James Homer Wright in 1902 published[18] a method using heat to polychrome the methylene blue, which he combined with eosin Y.
[13][6][26] Giemsa attempted to use combinations of pure dyes rather than polychromed methylene blue solutions which are highly variable in composition.
[23][19] Giemsa stain powders produced in Germany were widely used in the United States until the interruption of the supply during World War I, which caused increased utilization of James Homer Wright's method for polychroming methylene blue.
