Opal Blue
Historical document, translated for reference. It reflects medical knowledge of the 1920s–30s and is not medical advice.
Summary
Opal Blue is an alkaline salt of the mono-, di-, or tri-sulfonic acid of mono-, di-, or tri-phenyl-rosaniline. It is used as a background (plasma) stain after nuclei staining with hematoxylin (Foole) or carmine (Duval), and also in mixtures with other stains. It is also used for impregnating certain cavities like bone lacunae.
Encyclopedia entry (1928–1936)
Opal Blue, an alkaline salt (mono-, di-, tri-) of the sulfonic acid of mono- (di-, tri-)phenyl-rosaniline. Used as a background (plasma) stain after staining nuclei with hematoxylin (Foole) or carmine (Duval), as well as in mixtures with other stains (Biihler, Mallory, Lowenstein, Loeb, Kazakov, Heidenhain). The alcohol-soluble and water-insoluble sulfonic acid is used for impregnating certain cavities, for example bone lacunae, where the dye remains after the alcohol evaporates and makes them clearly visible on mounts embedded in Canadian balsam. Epstein proposed using the O. dye to detect Treponema pallidum (the syphilis spirochete) in liquid material. The procedure is the same as in Burri's method with India ink, with the spirochetes appearing uncolored against a blue background.
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Cite this page
“Opal Blue.” Soviet Medical Encyclopedia. English translation of Bolshaya Meditsinskaya Entsiklopediya, 1st ed. (Moscow, 1928–1936), ed. N. A. Semashko. https://sovietmedicalencyclopedia.pages.dev/article/opal-blue/