Eventually, Chargaff came to the conclusion that in a single molecule of DNA, Guanine/Cytosine = Adenine/Thymine = 1. This concept would later become known as Chargaff’s Rules.

Many people believe that American biologist James Watson and English physicist Francis Crick discovered DNA in the 1950s. In reality, this is not the case. Rather, DNA was first identified in the late 1860s by Swiss chemist Friedrich Miescher.

The first half of 20th-century science belonged to physics, with the general theory of relativity, quantum mechanics, and nuclear fission. The second half would belong to biology.

DNA was discovered in 1869 by Swiss researcher Friedrich Miescher, who was originally trying to study the composition of lymphoid cells (white blood cells). Instead, he isolated a new molecule he called nuclein (DNA with associated proteins) from a cell nucleus.

Erwin Chargaff was one of those men, making two discoveries that led James Watson and Francis Crick to the double helix structure of DNA. At first, Chargaff noticed that DNA – whether taken from a plant or animal – contained equal amounts of adenine and thymine and equal amounts of cytosine and guanine.

He fractionated out nuclei from cells. He then isolated the DNA from the nuclei and broke it down into its constituent nucleic acids. Chargaff drew the conclusion that it is in fact the DNA in the nucleus of the cell that carries genetic information rather than the protein.

Photograph 51, or Photo 51, revealed information about DNA´s three-dimensional structure by displaying the way a beam of X-rays scattered off a pure fiber of DNA. In 1962, after Franklin´s death, Watson, Crick, and Wilkins shared the Nobel Prize in Physiology or Medicine for their findings about DNA.

Watson and Crick worked together on studying the structure of DNA (deoxyribonucleic acid), the molecule that contains the hereditary information for cells. In April 1953, they published the news of their discovery, a molecular structure of DNA based on all its known features – the double helix.

On February 28, 1953, Cambridge University scientists James D. Watson and Francis H.C. Crick announce that they have determined the double-helix structure of DNA, the molecule containing human genes.

Deceased (1916–2004)

The function of DNA? depends to a large extent on its structure. The three-dimensional structure of DNA was first proposed by James Watson and Francis Crick in 1953. KEY FACTX-ray diffraction of DNA crystals results in a cross shape on the X-ray film, which is typical of a molecule with a helix shape.

The Nobel Prize in Physiology or Medicine in 1962 was awarded to James Watson, Francis Crick and Maurice Wilkins for their discovery of the molecular structure of DNA, which helped solve one of the most important of all biological riddles.

In the 1950s when Watson and Crick were working on their model of DNA, many scientists did not think that DNA carried the genetic code.

Albert Luthuli

Marie Curie

Wangari Maathai

Here are the 10 countries with the most Nobel Prize winners:

• United States (375)
• United Kingdom (131)
• Germany (108)
• France (69)
• Sweden (32)
• Russia (31)
• Japan (27)
• Canada (26)

Malala Yousafzai

In 1973 Patrick White was awarded the Nobel Prize in Literature. White’s work explores some of humankind’s great existential questions in a distinctly Australian environment.

Julia Gillard (27th Prime Minister, 2010–13) is the first female Prime Minister of Australia.