From DNA to RNA

Abstract

The paths to scientific discovery and innovation are notoriously complex and winding, and those that led to the discovery of DNA and messenger RNA (MRNA) are no exception. Let us recall, then, the most eminent facts that led to the fundamental principle of molecular biology. In 1869, a Swiss doctor, Friedrich Miescher, who was almost deaf and, partly for this reason, unwilling to pursue a career in health care, while in the kitchen of the castle of Tübingen (Germany), which had been transformed into a laboratory, discovered a substance rich in phosphate and nitrogen from the nuclei of blood cells obtained from patients treated at the Tübingen hospital. He claimed that this substance, which he called “nuclein”, was neither a sugar, nor a lipid, nor a protein: it was a new biological substance. Back in Switzerland, after two years of research in Tübingen, he continued his research in Basel, this time using cells of the sperm of the Rhine salmon. He isolated nuclein again. His students and successors continued to study nuclein, to define its composition and content: it consists of four basic elements called adenine, thymine, guanine and cytosine, which are associated with a phosphate bond.