methylene blue

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.

methylene blue

noun

1. 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 Also calledmethylthionine chloride

methylene blue

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.

Word History and Origins

Origin of methylene blue¹

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

The woman was treated with an antidote methylene blue, and within minutes reported feeling better.

From The Guardian

The dye in question is methylene blue, and it creates an intense sapphire color.

From The Verge

Dutch, American and Malian scientists working in Ouélessébougou, Mali, found that adding methylene blue to a typical treatment regimen cleared gametocytes from the bloodstream within two days.

From New York Times

They also said Effexor’s label did warn of potential interaction with methylene blue, but the hospital where Pope had surgery failed to catch it.

From Washington Times