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GC-content

percentage of guanine and cytosine in DNA or RNA molecules

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Record originEnglish Wikipedia
Text licenseCC BY-SA 4.0
Source revisionAug 29, 2026
Entity authorityQ933491 ↗
Source-derived summary

In molecular biology and genetics, GC-content (or G+C content or guanine-cytosine content) is the percentage of nitrogenous bases in a DNA or RNA molecule that are either guanine (G) or cytosine (C). This measure indicates the proportion of G and C bases out of an implied four total bases, also including adenine and thymine in DNA and adenine and uracil in RNA.

GC-content may be given for a certain fragment of DNA or RNA or for an entire genome. When it refers to a fragment, it may denote the GC-content of an individual gene or section of a gene (domain), a group of genes or gene clusters, a non-coding region, or a synthetic oligonucleotide such as a primer.

Structure

Qualitatively, guanine (G) and cytosine (C) undergo a specific hydrogen bonding with each other, whereas adenine (A) bonds specifically with thymine (T) in DNA and with uracil (U) in RNA. Quantitatively, each GC base pair is held together by three hydrogen bonds, while AT and AU base pairs are held together by two hydrogen bonds. To emphasize this difference, the base pairings are often represented as "G≡C" versus "A=T" or "A=U".

DNA with low GC-content is less stable than DNA with high GC-content; however, the hydrogen bonds themselves do not have a particularly significant impact on molecular stability, which is instead caused mainly by molecular interactions of base stacking. Because of the thermostability of GC pairs, it was once presumed that high GC-content in DNA was a necessary adaptation to high temperatures, though this hypothesis was later refuted in 2001 by comparative analysis of over 100 prokaryotes. Furthermore, P. putrefaciens, a species of bacteria with high GC-content DNA, has been observed to undergo autolysis more readily, thereby reducing the overall longevity of the cell. Even so, it has been shown that there is a strong correlation between the optimal growth of prokaryotes at higher temperatures and the GC-content of structural RNAs, such as ribosomal RNA, transfer RNA, and many other non-coding RNAs. The AU base pairs are less stable than the GC base pairs, making high-GC-content RNA structures more resistant to the effects of high temperatures.

Editorial summary

“GC-content” enters the record as percentage of guanine and cytosine in DNA or RNA molecules. Crown Archives preserves that source wording while asking what GC-content, percentage and guanine can confirm, complicate or overturn.

Editorial reviewA concise reference frame for defining the subject, testing terminology and identifying the institution closest to the evidence. The current lead gives the account dated anchors—2001—that can be checked directly. The selected authority fields contribute no independent date. Its strongest next move is a source search built around GC-content, percentage and guanine.
Editorial analysis

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“GC-content” is worth following because a concise public description often conceals a longer documentary argument. Here, GC-content, percentage and guanine provides the most credible route into that argument.

Evidence profile

Vocabulary and entity names are the principal evidence signals here, because they determine the precision of every later search. The source revision retrieved here is dated Aug 29, 2026. The linked authority identifier is Q933491. None of the 0 selected statements returned an explicit reference. The first chronological checks are 2001.

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Source & attribution

This entry incorporates text from “GC-content” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.