DNA

noun

ˌdē-ˌen-ˈā 

: any of various nucleic acids that are usually the molecular basis of heredity, are constructed of a double helix held together by hydrogen bonds between purine and pyrimidine bases (see base entry 1 sense 6b) which project inward from two chains containing alternate links of deoxyribose and phosphate, and that in eukaryotes are localized chiefly in cell nuclei compare recombinant dna

Illustration of DNA

• A molecular model
• 1 hydrogen
• 2 oxygen
• 3 carbon in the helical phosphate ester chains
• 4 carbon and nitrogen in the cross-linked purine and pyrimidine bases
• 5 phosphorus
• B double helix

Examples of DNA in a Sentence

Recent Examples on the Web

Prosecutors said subsequent laboratory testing confirmed traces of Tobin’s DNA were found in the examination. —Rosalio Ahumada, Sacramento Bee, 8 Apr. 2024

Inspector Kevin Kentish of the homicide division attributed the arrest to advances in DNA technology and to the fresh perspective that a new generation of detectives brought to the case. —Keith L. Alexander, Washington Post, 28 Mar. 2024

SNPs occur normally throughout DNA and each human genome has about four to five million of them. —Laura Baisas, Popular Science, 28 Mar. 2024

The researchers confirmed the shrimp was a new species using DNA collected from its leg, according to the study. —Irene Wright, Miami Herald, 28 Mar. 2024

Genetic testing analyzes the DNA to check for genetic abnormalities.26 This process is expensive: One cycle may cost as much as $17,000 without health insurance. —Wendy Wisner, Health, 27 Mar. 2024

If not kept in check, free radicals react with other chemicals in the body and can damage fatty tissue, DNA, and proteins, leading to diseases such as diabetes and cancer. —Kaitlin Sullivan, Health, 16 Mar. 2024

But Graves said the rate grew after the de-accreditation of the city’s troubled D.C. forensic lab, which required prosecutors to use federal agencies and private laboratories to make up the slack and process evidence involving drugs, firearms and DNA. —Emily Davies, Washington Post, 15 Mar. 2024

In November 2002, Mesa police linked both attacks based on a DNA match, the county attorney's office noted. —Jose R. Gonzalez, The Arizona Republic, 15 Mar. 2024

Word History

Etymology

deoxyribonucleic acid

First Known Use

1944, in the meaning defined above

Phrases Containing DNA

• DNA fingerprinting
• DNA test
• DNA virus
• DNA phenotyping
• DNA polymerase
• DNA methylation
• satellite DNA
• mitochondrial DNA
• junk DNA
• recombinant DNA

Kids Definition

DNA

noun

ˌdē-ˌen-ˈā 

: any of various nucleic acids that are located especially in cell nuclei, are usually the chemical basis of heredity, and are composed of two nucleotide chains held together by hydrogen bonds in a pattern resembling a flexible twisted ladder compare rna

Medical Definition

DNA

noun

ˌdē-ˌen-ˈā 

: any of various nucleic acids that are usually the molecular basis of heredity, are constructed of a double helix held together by hydrogen bonds between purine and pyrimidine bases which project inward from two chains containing alternate links of deoxyribose and phosphate, and that in eukaryotes are localized chiefly in cell nuclei

called also deoxyribonucleic acid

see recombinant dna