DNA's Discovery

Events

Fredrick Griffith

1928

Identified the process of transformation in bacteria

Avery, McCarty and Macleod

1944

Isolated DNA and identified it as the molecule which carried on transformation.

Franklin and Wilkins

1950

Purified and photographed DNA using c-ray diffraction.

Chargaff

1950

Determined that these pairs always occur in equal numbers.

Watson and Crick

1950

Developed a model for DNA structure which they called a double helix

Hershey and Chase

1952

Used radioactive isotopes to label DNA in bacteriophages and determined that DNA was responsible for transformation.