Rosalind Franklin’s contemporary title as the “Dark Lady of DNA” was originally meant as an insult by one of her coworkers. But many others in the present day, like her biographer Brenda Maddox, see it as proof of her strong influence on science. Franklin was the biochemist who, in 1952, was the first to discover that DNA was double-helix-shaped after taking Photo 51 with her assistant. Her legacy inspired the European Space Agency to name an ExoMars Rover for her in 2019. It’s a fitting name since this rover – set to launch later this decade – is programmed to search for genetic molecules or compounds to prove if there was ever life on Mars. 

Franklin was born July 25, 1920, in the Notting Hill neighborhood of London, England. The Franklins were a prominent British Jewish family; many of her relatives were involved in British politics, and some were even activists for women’s suffrage. Her father Ellis taught classes about magnetism and electricity at the Working Men’s College of London and greatly encouraged his daughter to study science as she grew up. Franklin studied natural sciences at Newnham College at the University of Cambridge, where she graduated from her initial studies in 1941.

In 1945, Franklin earned a PhD from the University of Cambridge, for her thesis exploring the density and porosity of coal. Two years later, she got a job as a researcher in the Laboratoire Central des Services Chimiques de l'État in Paris, France. Here she learned X-ray crystallography. This process, also called X-ray diffraction, involves reflecting X-rays off of crystals in order to determine the crystal’s structure and makeup. At the Laboratoire, Franklin used this method to examine different types of coal, thus building off of her thesis research. She published her work in a 1951 paper in the prestigious scientific journal, Proceedings of the Royal Society.

In late 1951, she moved back to London to work as a research associate at King’s College. Her new assistant in DNA research was a graduate student named Raymond Gosling. By the end of the year she discovered that DNA could exist either as a thin fiber at a relatively high humidity (in a “wet” form called A-DNA), or in dry conditions in a compact form (in a “crystalline” form called B-DNA). At this point, results were still inconclusive about A-DNA’s shape, but the research team had concluded that B-DNA was definitely a helix. In fact, Franklin and Gosling’s famous Photo 51 (taken in 1952) was of B-DNA. 

However, in the moment, Franklin was not as excited about Photo 51 as Gosling was. Not only was she more focused on solving the A-DNA mystery, but she was also about to leave her position at King’s College. As a result, Gosling was assigned to a new graduate advisor, Maurice Wilkins. Once Franklin officially left a few days later, Gosling showed the photo to Wilkins – and Wilkins then showed it to his other co-workers, James Watson and Francis Crick. 

In 1953, the scientific journal Nature published Watson and Crick’s chemical model of a DNA double helix molecule. Their model was published alongside their data on the subject – as well as articles by Franklin, Gosling, and Wilkins. However, Watson and Crick only cited their names in a footnote, mentioning that they had “been stimulated by a general knowledge of Franklin [and Gosling] and Wilkins' ‘unpublished’ contribution.” Nine years later, Watson, Crick, and Wilkins received the Nobel Prize in Physiology or Medicine for their partial efforts. 

Meanwhile, by 1953, Franklin had moved to a new position at Birkbeck College in London, where she pivoted to studying RNA. While there, she used X-ray crystallography to study RNA viruses such as the tobacco mosaic virus. Years later, this inspired her to research the makeup of the polio virus. She chose polio specifically after her 1956 visit to the University of California, Berkeley, where researchers there suggested it to her. Though the research was done in London, her grant money came from the US Public Health Service of the National Institutes of Health. 

However, later that same year, Franklin was diagnosed with ovarian cancer. Throughout her illness, Franklin continued her crystallography research of polio – alive strands of polio, much to her colleagues’ horror – all through 1957. Her research team would eventually conclude that the polio molecule has icosahedral symmetry (or that it has 60 sides, like a soccer ball). Franklin would not live to see these discoveries published, however. She succumbed to the cancer on April 16, 1958. 

Franklin’s discoveries have greatly changed our view of DNA, RNA, and polio, even today. She was a groundbreaking researcher whose legacy continues to inspire scientists and students around the world. The Rosalind Franklin University of Medicine and Science in Chicago was renamed for her in 2004. In 1997, an asteroid was named in her honor. And hopefully sometime in the not too distant future, a rocket will launch to Mars carrying a rover bearing her name — on a mission to search for the building blocks of life and potentially change how we think about life on — and off — Earth.

This blog was published as part of the Museum's Sally's Night celebration, spotlighting women and underrepresented genders in STEM.