DNA Project Timeline

Main

Oswald Avery

1913

He identified a complex carbohydrate called polysacharide.

Frederick Griffith

1928

He showed that lobar pneumonia could transform from one strain into a different strain. This was later identified as DNA.

Oswald Avery

1944

He showed that Frederick griffith's transforming principle was DNA.

Erwin Chargaff

1951

Chargaff had 2 main rules named after him. They stated that the number of guanine inits is eual to the number of cytosine units. Likewise with adenine and thymine.

Linus Pauling

1951

Linus Pauling determined that the structure of a class of proteins is a helix.

Alfred Hershey and Marsha Chase

1952

The Hershey-Chase experiments confirmed that DNA was genetic material. Hershey and Chase showed that when bacteriophages, infect bacteria, their DNA enters the host bacterial cells, but most of their protein does not..

Rosiland Franklin

1952

Franklin was an expert x-ray crystallographer. Her work on the x-ray diffraction images of DNA led to the discovery of the DNA double helix. Her data was used in Crick adn Watson's hypothesis on the structure of DNA.

James Watson and Francis Crick

1953

Discovered DNA double helix using models and data gathered from other scientists.