The discovery of DNA

The middle of the 20th century witnessed some of the most fundamental discoveries in DNA research. In 1944 Oswald T. Avery and colleagues published their landmark paper suggesting that DNA was the carrier of genetic information. A little later, Erwin Chargaff discovered that the base composition of DNA varies between species, but that within each species the bases are always present in fixed ratios. In 1952 Alfred Hershey and Martha Chase confirmed DNA as the genetic material. One year later, building on X-ray analyses by Rosalind Franklin and Maurice Wilkins, Francis Crick and James Watson famously solved the structure of DNA. Finally, by the mid-1960s the genetic code had been cracked. Thus, over a period of around 20 years, many of DNA’s secrets had been uncovered.

The importance of these breakthroughs often overshadows the fact that research into DNA had already begun 75 years before these events took place, with the discovery of DNA by Johann Friedrich Miescher in 1869.

It was in 1869 that the young Swiss biochemist Friedrich Miescher was the first to isolate DNA. At the time he had just moved from his native Basel to the medieval university town of Tuebingen in Germany. He was working in a laboratory located in the former kitchen of Tuebingen’s castle – high above the roofs of the old town. Choosing white blood cells as his starting material, Miescher wanted to uncover the chemical nature of cells .

The discovery of DNA thus had a very unsavoury beginning: He isolated the cells he needed for his experiments from bandages contaminated with pus. Following the initial characterisation of the mysterious substance, he discovered that DNA was also present in the nuclei of other cells, including sperm. This even led to speculations that DNA – or nuclein as Miescher called it – might be responsible for the transmission of hereditary traits. But it took another 70 years before Avery and his colleagues proved these initial speculations to be right.

Publications by Ralf Dahm on the discovery of DNA:

Dahm, R: Discovering DNA: Friedrich Miescher and the early years of nucleic acid research. Human Genetics, 2008, Vol. 122(6), p. 565-581.

Dahm, R: Friedrich Miescher and the discovery of DNA. Developmental Biology, 2005, Vol. 278(2), p. 274-288.

Dahm, R: The discovery of DNA, circa 1869. The Scientist (2008), Vol. 22, Issue 12, p. 84.

Dahm, R: Die Entdeckung der DNA. BIOspektrum (2008), Vol. 07.08, p. 767-768.

Dahm, R: The First Discovery of DNA. American Scientist (2008), Vol. 96, July-August issue, p. 320-327.

Dahm, R: Festpäckchen mit DNA-Knüller. Leipziger Volkszeitung, Ausgabe vom 18./19. Dezember 2004, Seite M 2.

Dahm, R: The molecule from the castle kitchen. Max-Planck-Research (2004), Issue 2/2004, p. 50-55.

Dahm, R: Das Molekül aus der Schlossküche. Max-Planck-Forschung (2004), Ausgabe 1/2004, S. 50-55.

Dahm, R: Friedrich Miescher: Ein Basler auf der Spur des Lebens. Basler Zeitung, 14. Oktober 2003, Seite 3.

Dahm, R.: Menschen – Johann Friedrich Miescher. Biologie in unserer Zeit (BiuZ), Verlag Wiley-VCH), Ausgabe 3, Mai 2003, S. 202.

Dahm, R.: In der Tübinger Schlossküche wurde die DNA entdeckt. Schwäbisches Tagblatt, 26. April 2003, Seite 26.

Publications on other aspects of the history of science:

Dahm, R: Alzheimer’s pathology, circa 1906. The Scientist (2009), Vol. 23, Issue 3, p. 84.

Three part series on Charles Darwin and his Theory of Evolution:

Dahm, R: Charles Darwin I: Die Anfänge der Evolutionstheorie. BIOspektrum (2009), Vol. 01.09, p. 96-97.

Dahm, R: Charles Darwin II: Die „natürliche Selektion“ als Motor der Evolution. BIOspektrum (2009), Vol. 02.09, p. 210-212.

Dahm, R: Charles Darwin III: Die Evolutionstheorie revolutioniert die Biologie. BIOspektrum (2009), Vol. 03.09, p. XXX. (in press)

Dahm, R: Menschen: Vor hundert Jahren – Alois Alzheimer beschreibt eine rätselhafte Krankheit. Biologie in unserer Zeit (Verlag Wiley-VCH), Volume 37(1), 2007, p. 65-66.

Dahm, R (2006): Alzheimer’s Discovery. Current Biology, Vol. 16(21), p. R906-910.

Dahm, R: Alois Alzheimer and the beginnings of research into Alzheimer’s disease. pp. 31-43. In „Alzheimer: 100 Years and Beyond“, Jucker M, Beyreuther K, Haass C, Nitsch RM, Christen Y (eds.). Springer-Verlag Berlin Heidelberg 2006.