DNA … the almost picture.
DNA is short for deoxyribonucleic acid. It is an essential molecule for life. It acts like a recipe holding the instructions telling our bodies how to develop and function. Most DNA molecules consist of two biopolymer strands coiled around each other to form a double helix. About 99.9 percent of the DNA of every person on the planet is exactly the same. It’s that 0.1 percent that is different that makes us all unique.
DNA was first isolated and identified by Swiss biologist Friedrich Meischer in 1869. In 1953, James Watson and Francis Crick suggested what is now accepted as the first correct double-helix model of DNA structure in the journal Nature. They jointly received the Nobel Prize for their discoveries.
Their double-helix, molecular model of DNA was then based on one X-ray diffraction image, labeled as “Photo 51”. It was taken by Rosalind Franklin and Raymond Gosling in May 1952 at King’s College, London. The photograph was critical evidence in identifying the structure of DNA.
But … back in 1951, a micro-biologist at Leeds University called William Astbury was also working on the structural nature of DNA. Astbury’s lab produced another important photograph of DNA. This was taken by Elwyn Beighton. The central black cross pattern is a result of the helical shape of the DNA molecule and shows remarkable similarity to the photograph taken in the following year by Rosalind Franklin. At that time, very few people knew how to interpret the diffraction patterns given by helical structures and in 1951, no one at Leeds appreciated the significance of this picture. If they had, Leeds might have played a very different role in the DNA story. The Nobel Prize may well have gone elsewhere …