methylene blue

American  

noun

Chemistry, Pharmacology.

1. a dark-green, crystalline compound, C 1 6 H 1 8 ClN 3 S, that dissolves in water to form a deep-blue solution: used chiefly as a dye, as a bacteriological and biological stain, and as an antidote for cyanide poisoning.

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methylene blue British  

noun

1. Also called: methylthionine chloride.  a dark-green crystalline compound forming a blue aqueous solution, used as a mild antiseptic and biological stain. Formula: C 16 H 18 N 3 SCl.3H 2 O

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methylene blue Scientific  

1. A basic dye that forms a deep blue solution when dissolved in water. It is used as an antidote for cyanide poisoning and as a bacteriological stain. Chemical formula: C ₁₆ H ₁₈ N ₃ SCl.

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Etymology

Origin of methylene blue

First recorded in 1885–90

Example Sentences

To gauge the fat content of the cream brought by farmers, the dairy would insert methylene blue in a sample and waited for its lactic acid to dissolve the color.

From New York Times • Jan. 9, 2023

The oxidized form of methylene blue is reduced by NADH, and its reduced form is oxidized by O2.

From Textbooks • Jun. 9, 2022

Explain the use of methylene blue as an antidote for rotenone poisoning.

From Textbooks • Jun. 9, 2022

They tested a modified version of methylene blue — an outdated treatment for malaria, urinary tract infections and bipolar disorder — in a dosing and efficacy trial of 321 people with mild-to-moderate Alzheimer's disease.

From Nature • Jul. 13, 2011

Various medicinal agents, such as carbolic acid administered subcutaneously and methylene blue fed in large quantities, have been recommended, but have failed to stand the tests of scientific investigation and practical use.

From Special Report on Diseases of Cattle by United States. Bureau of Animal Industry