Emmanuelle Charpentier and Jennifer Doudna are the first two women to share the prize, awarded for their work on the technology of genome editing.
Their discovery, known as Crispr-Cas9 genetic scissors, is a way of making specific and precise changes to the DNA contained in living cells.
They are the first women to share the prize without a male collaborator.
The winners will share the prize money of 10 million kronor (£861,200).
“When it happens, you’re very surprised, and you think it’s not real. But obviously it’s real,” she said.
During Emmanuelle Charpentier’s studies of the bacterium Streptococcus pyogenes, she discovered a previously unknown molecule called tracrRNA. Her work showed that tracrRNA is part of the organism’s immune defences.
This system, known as CRISPR/Cas, disarms viruses by cleaving their DNA.
In 2011, the same year she published this work, Charpentier began a collaboration with Prof Doudna, from the University of California, Berkeley, to recreate the bacterium’s genetic scissors in a test tube. They also worked on simplifying the scissors’ molecular components so they were easier to use.
In their natural form, the bacterial scissors recognise DNA from viruses. But Charpentier and Doudna showed that they could be reprogrammed to cut any DNA molecule at a predetermined site. Cutting the DNA then allows the code of life to be rewritten.
Commenting on the discovery, biological chemist Pernilla Wittung-Stafshede, said: “The ability to cut DNA where you want has revolutionised the life sciences.”
Chemist Claes Gustafsson added: “We can edit any genome, we can ask all kinds of questions,” adding that it could be harnessed to treat genetic diseases.
On being one of the first two women to share the prize, Prof Charpentier said: “I wish that this will provide a positive message specifically for young girls who would like to follow the path of science…and to show them that women in science can also have an impact with the research they are performing.”
She continued: “This is not just for women, but we see a clear lack of interest in following a scientific path, which is very worrying.”
Swedish industrialist and chemist Alfred Nobel founded the prizes in his will, written in 1895 – a year before his death.
2019 – John B Goodenough, M Stanley Whittingham and Akira Yoshino share the prize for their work on lithium-ion batteries.
2017 – Jacques Dubochet, Joachim Frank and Richard Henderson were awarded the prize for improving images of biological molecules
2016 – Jean-Pierre Sauvage, Fraser Stoddart and Bernard Feringa shared the prize for the making machines on a molecular scale.
2015 – Discoveries in DNA repair earned Tomas Lindahl and Paul Modrich and Aziz Sancar the award.
2014 – Eric Betzig, Stefan Hell and William Moerner were awarded the prize for improving the resolution of optical microscopes.
2013 – Michael Levitt, Martin Karplus and Arieh Warshel shared the prize, for devising computer simulations of chemical processes.
2012 – Work that revealed how protein receptors pass signals between living cells and the environment won the prize for Robert Lefkowitz and Brian Kobilka.