In 1953, using x-ray diffraction data collected by Rosalind Franklin, James D. Watsonand Francis Crick proposed the double helix structure of deoxyribonucleic acid (DNA). Their paper, “Molecular Structure of Nucleic Acids: A Structure of Deoxyribonucleic Acid”, proposed a simple and elegant solution to the then unknown chemical structure of DNA. It also provided an insight into how genetic instructions are stored inside organisms and passed from one generation to the next. This discovery was the end of a story that began a century earlier with an unknown 25-year-old Swiss physician, named Johannes Friedrich Miescher.
In 1868, working at the University of Tübingen, Miescher performed experiments on the chemical composition of leukocytes, using puss from discarded surgical bandages. He discovered a new type of cellular material that was not a protein and contained large amounts of phosphorous. Since he had isolated it from the cell nuclei, he named it nuclein (now nucleic acids). He discovered that this substance was not only found in puss cells, but in cells from yeasts, liver and kidney, and then went on to prove that nucleic acids were a characteristic component of all cell nuclei.