guanine

noun

gua·​nine ˈgwä-ˌnēn How to pronounce guanine (audio)
: a purine base C5H5N5O that codes genetic information in the polynucleotide chain of DNA or RNA compare adenine, cytosine, thymine, uracil

Examples of guanine in a Sentence

Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Future medical devices To map this phenomenon, the team manipulated the guanine crystals using electromagnets to shift their positions while exposing them to an external light source. Mrigakshi Dixit, Interesting Engineering, 26 May 2026 The bases are split into two categories: purines (adenine and guanine) and pyrimidines (thymine, cytosine and uracil). Devika Rao, TheWeek, 24 Mar. 2026 Scientists have discovered that a sample of the Ryugu asteroid collected by Japan's Hayabusa 2 spacecraft contains the nucleobases adenine, guanine, cytosine, thymine and uracil, the building blocks of DNA and RNA upon which all life is based. Robert Lea, Space.com, 17 Mar. 2026 Temozolomide—the standard of care for glioblastoma—works by depositing a methyl group onto the DNA of cells, specifically on guanine, one of DNA’s four base molecules. Isabella Backman, Hartford Courant, 27 Jan. 2026 See All Example Sentences for guanine

Word History

Etymology

guano + -ine; from its being found especially in guano

First Known Use

1850, in the meaning defined above

Time Traveler
The first known use of guanine was in 1850

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Cite this Entry

“Guanine.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/guanine. Accessed 4 Jun. 2026.

Kids Definition

guanine

noun
gua·​nine ˈgwän-ˌēn How to pronounce guanine (audio)
: a purine base that codes genetic information in DNA and RNA compare adenine, cytosine, thymine, uracil

Medical Definition

guanine

noun
gua·​nine ˈgwän-ˌēn How to pronounce guanine (audio)
: a purine base C5H5N5O that codes genetic information in the polynucleotide chain of DNA or RNA compare adenine, cytosine, thymine, uracil

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