double helix

noun

: a helix or spiral consisting of two strands in the surface of a cylinder that coil around its axis

especially : the structural arrangement of DNA in space that consists of paired polynucleotide strands stabilized by cross-links between purine and pyrimidine bases compare alpha-helix, watson-crick model

double-helical

ˌdə-bəl-ˈhe-li-kəl 

-ˈhē-

adjective

Examples of double helix in a Sentence

Recent Examples on the Web

One of these is based on the CRISPR/Cas9, which makes a break in both strands of DNA's double helix at a specific sequence that matches what's called a guide RNA. —John Timmer, Ars Technica, 4 Mar. 2025

Vincent Callebaut Architectures' eye-catching twisting residential tower takes the form of a DNA's double helix in Taipei, Taiwan. —Adam Williams, New Atlas, 25 Dec. 2024

This elegant double helix of a novel entwines the stories of a fictional modern-day British girl and a real-life 15th-century Italian painter. —New York Times, 8 July 2024

If that atom happens to be part of a DNA molecule, the result can be a breakage in one or both of the delicate strands that wind into the famous double helix. —Tom Hawking, Popular Science, 24 Oct. 2024

Word History

First Known Use

1954, in the meaning defined above

Rhymes for double helix

• felix

Kids Definition

double helix

noun

: the arrangement in space of DNA that resembles a spirally twisted ladder with the sides made up of the sugar and phosphate units of the two nucleotide strands and the rungs made up of the pyrimidine and purine bases extending into the center and joined by hydrogen bonds

Medical Definition

double helix

noun

: a helix or spiral consisting of two strands in the surface of a cylinder that coil around its axis

especially : the structural arrangement of DNA in space that consists of paired polynucleotide strands stabilized by cross-links between purine and pyrimidine bases compare alpha-helix, watson-crick model

double-helical

-ˈhel-i-kəl  -ˈhē-li- 

adjective