DNA Discovery Timeline

Frederick Griffith

Jan 1, 1928

January 1928 he reported what is now known as Griffith's Experiment, the first widely accepted demonstrations of bacterial transformation, whereby a bacterium distinctly changes its form and function. He discovered pneumococcal transformation.

Oswald Avery

Dec 5, 1944

Avery was curious of frederick's discovery, so he began to experiment. He was the first to isolate nucleic acids from pneumococcus. He discovered that DNA transmits heredity.

Erwin Chargaff

May 5, 1950

Erwin Chargaff demonstrated three rules to DNA.
1. The number of adenine always equals number of thymine.
2. The number of guanine always equals the number of cytosine.
3. The number of purines always equals the number of pyrimidines.
These rules expanded DNA discoveries.

Rosalind Franklin

Nov 5, 1951

Rosalind Franklin discovered the double helix structure of DNA. She won the Nobel Peace Prize. She also produced the X-ray chrystallography pictures of BDNA which Watson and Kirk used to determine the structure of the double helix.

Alfred Hershey and Martha Chase

Jun 5, 1952

The Hershey-Chase experiments were a series of experiments conducted in 1952 by Alfed Hershey and Martha Chase that helped confirm that DNA is the genetic material. They also discovered things concerning the genetic structure of viruses.

Watson and Crick

Apr 25, 1953

Watson and Crick described the discovery of the double helix, which was originally found and noticed by Rosalind Franklin. They also created the first model of the double helix.