150 years of DNA

DNA has become the icon of modern bioscience but few people realize that it was Friedrich Miescher, who - almost a century before Watson and Crick - laid the chemical groundwork for the molecular breakthroughs that followed. Today, 150 years after Miescher's first 'discovery' of DNA, we want to highlight his remarkable work. Born in Basel in 1844, Friedrich Miescher grew up in a well-respected family that was part of the academic elite. His father was a physician and taught anatomy at the University of Basel; his uncle was an embryologist. After Miescher graduated from medical school in 1868, he decided to pursue a career in research. At the University of Tübingen in Germany, he studied under renowned chemist and physiologist Felix Hoppe-Seyler, a pioneer of biochemistry who had discovered hemoglobin just a few years before. The consensus at that time was that cells were largely made of proteins, therefore Miescher was particularly interested in these molecules. Choosing leucocytes as his source material - obtained from the pus on surgical bandages from a clinic nearby - he set out to isolate the different types of proteins that make up these cells. During his tests, he noticed something unexpected: a substance precipitated from the solution when he added acid, and dissolved again when he added alkali - unexpected properties that did not match those of proteins. Realizing the potential significance, Miescher developed new protocols that allowed him to cleanly separate and analyze this mysterious precipitate. A new class of cellular substance