James Watson and Francis Crick were giants in genomics. Their discovery of the double helix structure of DNA revolutionised our understanding of the human form and its past, present and future. However, it is a common misconception that James Watson and Francis Crick discovered DNA in the 1950s. Watson and Crick benefitted from pioneering predecessors, but to find the complete story of the discovery of DNA, we must go back to the 1800s.
“it is a common misconception that James Watson and Francis Crick discovered DNA in the 1950s”
James Dewey Watson (1928 – ) 
Francis Harry Compton Crick (1916 – 2004)
Discovering the molecule
The molecule, which we now refer to as DNA, was first identified in the 1860s by a Swiss chemist called Johann Friedrich Miescher. He was researching the key components of white blood cells, part of the body’s immune system, when he discovered a substance which he would call ‘nuclein’. What Miescher hadn’t realised is that he had just discovered the molecular basis of all life: deoxyribonucleic acid, also known as DNA .
“What Miescher hadn’t realised is that he had just discovered the molecular basis of all life”
Walther Flemming (1843 – 1905) 
Friedrich Miescher (1844 -1895) 
Albrecht Kossel (1853 -1927)
Many discoveries would follow, such as Abrecht Kossel’s ‘four building blocks of DNA’, and Walter Flemming’s ‘chromosome theory of inheritance’. Flemming, an anatomist from Germany, discovered a fibrous structure within the nucleus of cells. He named it ‘chromatin,’ but what he actually discovered was what we now know as Chromosomes.