DNA Timeline

1953 - James Watson and Francis Crick discover the double helix structure of DNA

1953 BCE

James Watson and Francis Crick publish their description of DNA. They describe it as a double-helix -two spirals held together by complementary base pairs.

1953 - George Gamow and the “RNA Tie Club”

1953 BCE

he created an exclusive club known as the “RNA Tie Club”, in which each member would put forward their ideas about how nucleotide bases were transformed into proteins by the body's cells. (1953-1996)- (various discoveries of individual genes for cystic fibrosis, Huntington's disease, etc. Also, genetically engineered food, and animal cloning.)

1952 - Rosalind Franklin photographs crystallized DNA fibres

1952 BCE

Maurice Wilkins and Rosalind Franklin image DNA crystals via X-ray. These images are the basis for the conclusions of Watson and Crick. Using the photographs, she calculated the dimensions of the strands and also deduced that the phosphates were on the outside of what was probably a helical structure.

1950 - Erwin Chargaff discovers that DNA composition is species specific

1950 BCE

Erwin Chargaff demonstrates that the bases of DNA are equal = there is an A for every T and a C for every G. In 1950,chemistry of nucleic acids: first, that in any double-stranded DNA, the number of guanine units is equal to the number of cytosine units and the number of adenine units is equal to the number of thymine units, and second that the composition of DNA varies between species. These discoveries are now known as 'Chargaff's Rules'.

1947-Chargaff's rules

1947 BCE

Working with a number of colleagues, including Ernst Vischer and Charlotte Green, Chargaff began getting interesting results in 1947. Chargaff prepared the DNA, its components for analysis by ultraviolet spectrophotometry. Although their early results were rather rough, Chargaff was reassured: they seemed to suggest there were real differences in DNA taken from different species.

1944 - Oswald Avery identifies DNA as the 'transforming principle'

1944 BCE

Avery had worked for many years with the bacterium responsible for pneumonia, pneumococcus, and had discovered that if alive but harmless form of pneumococcus was mixed with an inert but lethal form, the harmless bacteria would soon become deadly. Determined to find out which substance was responsible for the transformation. He soon noted that the substance did not seem to be a protein or carbohydrate but rather a nucleic acid, and with further analysis, it was revealed to be DNA.

Components of DNA discovered

1929 BCE

Phoebus Levene discovers deoxyribose sugar in nucleic acids. Later on, demonstrates that DNA is made up of nucleotides, which are composed of a deoxyribose sugar, a phosphate group, and a base.

Genetic factor in bacteria transferred

Period: 1928 BCE to 1 BCE

Frederick Griffith was doing an experiment with mice, he put the medical things in the mouses which cases bacteria, which then cause fatal pneumonia in the mice. He then determined that there must be a genetic factor that can transform the bacteria.

1902 - Sir Archibald Edward Garrod is the first to associate Mendel's theories with a human disease

1902 BCE

Whilst studying the human disorder alkaptonuria, he collected family history information from his patients. Through discussions with Mendelian advocate William Bateson, he concluded that alkaptonuria was a recessive disorder and, in 1902, he published The Incidence of Alkaptonuria

1869 - Friedrich Miescher identifies "nuclein"

1869 BCE

Material from the nucleus of a cell considered a single substance when first isolated in the late 1800s but later shown to consist of DNA and associated proteins.Friedrich Miescher describes an acidic substance in a cell's nuclei. This substance, first called nuclein, is now identified as DNA.