methylene blue

A basic dye easily oxidized to azure, with dye mixtures; used in histology and microbiology, to stain intestinal protozoa in wet mount preparations, to track RNA and RNase in electrophoresis, and as an antidote for methemoglobinemia; its redox indicator properties are useful in milk bacteriology.

- Kühne m. m. in absolute alcohol and phenol solution.

- Loeffler m. a stain for diphtheria organisms that contains m. in dilute ethanol plus a slight amount of potassium hydroxide; dye solution gives best results when aged to a polychrome state.

- new m. [C.I. 52030] a basic thiazin dye used for supravital staining of reticulocytes in blood smears.

- polychrome m. an alkaline solution of m. that undergoes progressive oxidative demethylation with aging (ripening) to produce a mixture of m., azures, and methylene violet; boiling with sodium carbonate or other oxidizing agents accomplishes this result quickly, although it is not as highly regarded.

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methylene blue n a basic thiazine dye C₁₆H₁₈ClN₃S·3H₂O used in the treatment of methemoglobinemia, as an antidote in cyanide poisoning, as a biological stain, and as an oxidation-reduction indicator

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a blue dye used to stain bacterial cells for microscopic examination.

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[USP] methylthionine chloride; dark green crystals or crystalline powder having a bronzelike luster, readily reduced to colorless leukomethylene blue, which in turn is readily oxidized to methylene blue. Administered orally or intravenously in the treatment of congenital methemoglobinemia and intravenously in the treatment of toxic methemoglobinemia, and used as a bacteriological, biologic, and pathologic stain, as a colorimetric indicator for redox reactions, as a surgical marker, and as a diagnostic aid in the detection of the premature rupture of fetal membranes and to identify separate amniotic sacs in multiple pregnancies. Called also Swiss b.