On December 10, 1962, the Nobel Prize in Physiology or Medicine was awarded to Francis Crick, James Watson, and Maurice Wilkins for their roles in discovering the double helix structure of DNA.
Francis Crick and James Watson surmised that DNA is composed of four molecules called bases: adenine, thymine, guanine, and cytosine. They determined that these bases consistently formed pairs (adenine with thymine, and guanine with cytosine) and that these base pairs were arranged in sequence along a phosphate backbone, but they did not know what the DNA structure looked like when all these bases were paired.
To figure out the structure of DNA, Crick and Watson built models of DNA, while Maurice Wilkins and his colleague Rosalind Franklin used a technology called X-ray crystallography to take pictures of actual DNA molecules with a microscope. These X-ray pictures provided clues of DNA's double helical structure. Crick and Watson saw the work that Wilkins and Franklin had done, specifically an X-ray crystallography picture of DNA known as photograph 51, and they realized the true double helix structure of DNA.
In April 1953, Crick and Watson published their findings in the journal Nature, stating that the DNA "structure has novel features which are of considerable biological interest." The discovery of the double helix structure of DNA allowed scientists to visualize how genetic information is stored, copied, and transmitted to the next generation. This discovery allowed for further insights into human genetics and cell biology, such as how proteins are produced from genes and the process by which DNA copies (replicates) itself during cell division. It also opened the door for advancements in biotechnology, including sequencing of the entire human genome.
Although Rosalind Franklin worked alongside Maurice Wilkins during the discovery of the double helix structure of DNA, she was not awarded the Prize. She died in 1958, four years before the award was given, and the Nobel Prize rules state that only living persons can be nominated.