Then
Her data was shown to Watson and Crick without her full knowledge, helping them build their double-helix model; she also led important studies of viruses.
Timeline of Discovery · 29 / 30
Rosalind Franklin
1920 - 1958 · England
Rosalind Franklin’s X-ray photographs — especially the celebrated Photo 51 — revealed the DNA double helix, though her contribution took years to be fully credited.
- Chemistry
- Biology
- Contemporary
Lived
1920 - 1958
Era
Contemporary
Primary field
Chemistry
Signature idea
X-ray crystallography that revealed DNA structure
Their place in history
1920 - 1958
The question they asked
What is the physical structure of DNA, the molecule that carries heredity?
The Contribution
What this scientist actually did — precisely and plainly.
Her sharp X-ray diffraction images of DNA fibres provided the key evidence that DNA is a helical molecule with features that only a double helix could explain.
How the Work Advanced Knowledge
The tools, experiments and reasoning behind the discovery.
She was an expert crystallographer who prepared pure DNA samples and interpreted diffraction patterns with mathematical rigour.
Why It Mattered Then / Today
From their own moment in history to the world we live in now.
Today
The double helix model she made possible spawned genetics, genomics and modern medicine; her story is a landmark in how science must credit and share work fairly.
Important Works or Discoveries
Landmarks that carried the idea into the world.
- Photo 51 X-ray diffraction image
- Nucleic acid diffraction studies
- Structural studies of viruses
Sources
Where this profile was verified.
Last reviewed: 2026-09-22
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