Watson–Crick model The double-stranded twisted ladder-like molecular structure of DNA as determined by James Watson and Francis Crick at Cambridge, England, in 1953. It is commonly known as the double helix.

Watson–Crick model The currently accepted model for the structure of DNA, as proposed by J. D. Watson and F. H. C. Crick (1953). It is suggested that DNA is composed of two right-handed, antiparallel polynucleotide chains coiled around a common axis to form a double helix. This structure is maintained by hydrogen bonds formed between the chains through the base pairing of adenine to thymine and cytosine to guanine.