The messenger: the structure of RNA

In the early part of the 20th Century, the nature of nucleic acid and what its role was within the cell were a bit of a mystery. DNA itself was first isolated as far back as 1869 by the Swiss chemist Johann Friedrich Miescher. He separated nuclei from the cytoplasm of cells and then isolated an acidic substance from these nuclei that he called nuclein1. Chemical tests by Miescher showed that nuclein contained large amounts of phosphorus and no sulphur, characteristics that differentiated it from proteins1. The first step in determining the structure of nucleic acid (either DNA or RNA) would be to identify its precise composition. RNA was considered a more approachable target for composition analysis because the simple treatment of RNA with hydroxide rapidly and completely hydrolyses the molecule to its individual component nucleotides. DNA, on the other hand, is resistant to such treatment.