DNA (deoxyribonucleic acid) is the molecule that stores our genetic information. It has a helical structure formed by two strands that each contain sequences of smaller molecules denoted by A’s, T’s, C’s, and G’s. This double-stranded helical structure was discovered in 1953 after years of experimentation by many individuals within the scientific community.
The Foundation
DNA was initially discovered by Friedrich Miescher who discovered the molecule in 1869. It was not until early in the 1940s that a team of scientists, led by Oswald Avery, posited that this mysterious molecule acted as our genetic material. Later in the decade, Erwin Chargaff realized that DNA contains equal amounts of A’s and T’s as well as equal amounts of G’s and C’s. This series of scientific developments, along with many others, led directly to the discovery of the structure of DNA.
Maurice Wilkins
In 1950, scientist Maurice Wilkins attended a lecture that led him to conclude that the structure of DNA could be revealed upon using X-ray crystallography. X-ray crystallography is a process in which a sample is made into crystals and exposed to X-rays. The patterns created by the bending of the X-ray beams, also known as diffraction patterns, are then analyzed to reveal information about the structure of the sample. While it was Wilkins who came up with the idea, he and graduate student Raymond Gosling worked together on the project.
Rosalind Franklin
After some initial progress, researcher Rosalind Franklin was invited to join the group by Wilkin’s boss, John T. Randall. However, Randall left Franklin with the impression that she and Gosling would be the only two working on the project. Additionally, Franklin was led to believe that she would lead the project while Wilkins assumed that she would be his assistant. This miscommunication led to a turbulent relationship between Franklin and Wilkins. Despite the conflict, Franklin and Gosling worked diligently for many months before finally capturing an image of the diffraction patterns created by crystallized DNA. Surprisingly, Franklin urged Gosling to give the image to Wilkins.
Watson and Crick
At this time, Wilkins had already developed friendly relationships with fellow scientists James Watson and Francis Crick. Watson and Crick were working together to discover the structure of DNA by utilizing research done by others in the field. They had been through several iterations of their DNA model and were worried that researcher Linus Pauling would discover the structure first when Wilkins shared Franklin and Gosling’s photo with them. The photo, simply named “Photo 51”, gave Watson and Crick the information they needed to create a model that accurately depicted the structure of DNA. For their contributions, Maurice Wilkins, James Watson, and Francis Crick were awarded the Nobel Prize in Physiology or Medicine in 1962. Rosalind Franklin, however, was not included in this group as she died in 1958 and the Nobel Prize is never awarded posthumously.
