The 2015 Nobel Prize in Chemistry has been awarded for discoveries in DNA repair. Tomas Lindahl and Paul Modrich and Aziz Sancar were named as the winners at a news conference in Stockholm, Sweden. Their work uncovered the mechanisms used by cells to repair damaged DNA – a fundamental process in living cells and important in cancer. Prof Lindahl is Swedish, but has worked in the UK for more than three decades. The prize money of eight million Swedish kronor (£634,000; $970,000) will be shared among the winners.

In the 1970s, scientists had thought that DNA was a stable molecule, but Prof Lindahl demonstrated that it decays at a surprisingly fast rate. This led him to discover a mechanism called base excision repair, which perpetually counteracts the degradation of DNA.

Turkish-born biochemist Aziz Sancar, professor at the University of North Carolina, Chapel Hill, US, uncovered a different DNA mending process called nucleotide excision repair. This is the mechanism cells use to repair damage to DNA from UV light – but it can also undo genetic defects caused in other ways.

The American Paul Modrich, professor of biochemistry at Duke University in North Carolina, demonstrated how cells correct flaws that occur as DNA is copied when cells divide. This mechanism, called mismatch repair, results in a 1,000-fold reduction in the error frequency when DNA is replicated.

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