How Did Rosalind Franklin’s Work In X Ray Crystallography Help Scientists Understand the Structure of DNA?

Rosalind Franklin’s contribution to the discovery of DNA structure was her photos of the molecule taken with X-ray crystallography.

The process had been developed by two British physicists, William Henry Bragg and his son, William Lawrence Bragg.

The son would later become head of the DNA research team at Cambridge University.

In X-ray crystallography, X-ray beams are sent through a crystal of a substance such as a fiber of DNA.

When the X rays strike the atoms in the crystal, they bounce off at an angle and make an image on photographic film. These images reveal how the atoms of the substance are arranged.

However, the arrangement is flattened into a two-dimensional picture. In the case of DNA, the three-dimensional model was needed to understand its structure.

If stretched out, a single strand of human DNA would be 3 feet long and contain 6 billion “steps” of information.

Linus Pauling had already won two Nobel Prizes when the DNA structure race began.

He won the Nobel Prize for chemistry in 1954 and the Nobel Peace Prize in 1962 for working to end nuclear weapons testing.