FACTS VIEWS VIS OBGYN, 2017, 9 (1): 57-61 History of medicine Rosalind Franklin (1920-1958) J. VAN ROBAYS Department of Pathology, ZOL, Campus St Jan, Schiepse Bos 6, 3600 Genk, Belgium. Correspondence at:
[email protected] Editing: Sien Ombelet Photo 51 and the unveiling of DNA amounts of A and T (adenine and thymine), and equal amounts of G and C (guanine and cytosine). DNA has been known for quite some time. In Those bases therefore had to be coupled somehow 1869, the Swiss biochemist Johann Miescher did to one another. a series of experiments on a cell type that was In the meantime, Oswald Avery discovered that then abundantly available: pus cells. From their DNA, at least in bacteria, was the carrier of genetic nucleus, he extracted a phosphoric substance he information. When scientists realized DNA might called nuclein. The function of this substance, later well be the source code of life itself – including in called deoxyribonucleic acid (DNA), was a mystery. human beings – they fervently started looking for Toward the end of the 1940’s, it was discovered that its structure. The greatest chemist of those days, it had to be an unbranched chain molecule. Erwin the American Linus Pauling, proposed an alpha Chargaff found out that it always contained equal helix structure in 1951, but unfortunately this did 57 not match the X-ray diffraction analysis. In January what she wanted to become: scientist. But her father 1953 he proposed a different DNA model – a triple thought higher education did not suit a woman, so spiral – but this too was incorrect.