“It has not escaped our notice that the specific pairing we have postulated immediately suggests a possible copying mechanism for the genetic material.”
—J.D. Watson and F.H.C. Crick
John Kendrew (left) and Max Perutz Maurice Wilkinstemporary logo Watson and Crick, 1953 DNA replication Watson and Crick along the backs
Linus Paulingtemporary logo Rosalind Franklin DNA x-ray difraction Watson presenting paper 1953 Symposium 1962 Nobel prize winners
1953 Nature paper Pomerat memo, 1953 Watson letter to Delbrucktemporary logo The Double Helix by James D. Watson Foreign editions of The Double Helix What Mad Pursuit by Francis Crick

The Double Helix

 By the early 1950s the tools were at hand for understanding the structure of DNA. The work of Avery and Hershey had shown that the secrets of the gene lay in this molecule. Chargaff’s discovery of the ratio of the bases provided a vital clue to the arrangement of its components. Laboratories in England, California, and elsewhere were using a technique called x-ray crystallography to reveal the structure of large molecules. In 1951, James Watson (1928-) and Francis Crick (1916-) joined forces at the Cavendish Laboratories at Cambridge University. It took them only two years to solve the problem: Watson and Crick published their DNA structure in the April 25, 1953 issue of the journal Nature.

"Secret of Life"

 The double-helix structure that Watson and Crick proposed for the DNA molecule immediately attracted attention. A crucial insight was the pairing of the bases, adenine with thymine, and guanine with cytosine. The structure suggested a way that genes could copy themselves, a process essential every time a cell divides. In effect, the double helix could unzip, each of its strands serving as a template for the formation of a new helix. As Crick put it, he and Watson had found “the secret of life.