methylene blue


Definition of methylene blue

: a basic thiazine dye C16H18ClN3S·3H2O used especially as a biological stain, an antidote in cyanide poisoning, and an oxidation-reduction indicator

Examples of methylene blue in a Sentence

Recent Examples on the Web Currently, only three dyes with fluorescent properties used as optical imaging contrast agents—methylene blue, indocyanine green and fluorescein—are approved for human use by the U.S. Food and Drug Administration (FDA). Courtney Sexton, Smithsonian Magazine, "Could Tattoo Ink Be Used to Detect Cancer?," 18 Sep. 2020 Warren’s patient recovered after two doses of methylene blue and an overnight stay at the hospital. Wire Service, The Mercury News, "A woman used a numbing agent to treat a toothache. The next day her blood turned blue," 19 Sep. 2019 The first-line treatment for the condition is a drug called methylene blue, which can spur the enzymatic reduction of the iron back to its normal state. Beth Mole, Ars Technica, "Blueish woman with chocolaty blood highlights rare risk of common anesthetic," 23 Sep. 2019 The woman in this case made a full recovery after intravenous treatment of methylene blue, her doctors reported in The New England Journal of Medicine. Beth Mole, Ars Technica, "Blueish woman with chocolaty blood highlights rare risk of common anesthetic," 23 Sep. 2019 Methemoglobinemia is easily treatable, using a medication that, perhaps ironically, is called methylene blue. NBC News, "A common numbing medication turned a woman's blood blue," 18 Sep. 2019 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. Donald G. Mcneil Jr., New York Times, "Promising Malaria Drug Has a Striking Drawback: Blue Urine," 9 Feb. 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'methylene blue.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

See More

First Known Use of methylene blue

1882, in the meaning defined above

Keep scrolling for more

Learn More about methylene blue

Time Traveler for methylene blue

Time Traveler

The first known use of methylene blue was in 1882

See more words from the same year

Statistics for methylene blue

Cite this Entry

“Methylene blue.” Dictionary, Merriam-Webster, Accessed 17 Jan. 2021.

Keep scrolling for more

More Definitions for methylene blue

methylene blue


Medical Definition of methylene blue

: 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

More from Merriam-Webster on methylene blue Encyclopedia article about methylene blue

Comments on methylene blue

What made you want to look up methylene blue? Please tell us where you read or heard it (including the quote, if possible).


Test Your Vocabulary

Words of Snow and Ice Quiz

  • image1037863653
  • Which of the following refers to thin, bending ice, or to the act of running over such ice?
True or False

Test your knowledge - and maybe learn something along the way.


Anagram puzzles meet word search.

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!