Rosalind Franklin - X-Ray Diffraction Image of DNA

Rosalind Franklin graduated from Cambridge University with a Ph.D. She then went and worked for John Randall as a research associate at Kings College in London. There, Franklin discovered that DNA can be in A form or B form. She developed a method to seperate the two forms providing the first DNA crystals pure enough to yield interpretable diffraction patterns. With this method a crystal is exposed to x-rays in order to produce a diffraction pattern.
Franklin discovered that the DNA helical structure has two strands not three sugar-phosphate backbones. Franklin gave details about the structures shape and size in her research. She could not find the bases paired on the inside of the helix; heredity. Rosalind left off here for Watson and Crick to discover the TOTAL DNA structure.(1)

Resources
1. Rosalind Franklin - access exellence