Discovery of Nucleic Acids, DNA
Only three years after Mendel's publication of Experiments on Plant Hybrids Friedrich Miescher (1844-1895) isolated DNA as a molecule from white blood cells, and famously from the pus of discarded surgical bandages, in 1869 (published in 1871).
Scientist mostly ignored both Mendel's and Miescher's work over a half a century. However, unlike Mendel who is widely known today by most people, Miescher's contributions to molecular biology and genetics are commonly unknown.Miescher called this nuclein and later in 1889 his student, Richard Altmann coined this molecule nucleic acid.
Between 1885 and 1901, Albrecht Kossel (1853–1927), a German scientist, isolated the chemical components of the nucleic acids. These are cytosine, guanine, thymine, and uracil.
Although scientists contemplated that nucleic acids had a significant biological function, this was long before these compounds were revealed as the bearers of all living beings’ genetic material – DNA and RNA.
Kossel was awarded the Nobel Prize in Physiology or Medicine in 1910 "in recognition of the contributions to our knowledge of cell chemistry made through his work on proteins, including the nucleic substances."
See also our blog "What is a Genome?"