Nobel Prize Museum. .Sancar's DNA model pictured, built in 1986, was used as a working tool as well as in his lectures to explain his discovery.

Living cells have DNA molecules that carry an organism's genes. For the organism to live and develop, its DNA cannot change. DNA molecules are not completely stable, and they can be damaged.

In 1983, through studies of bacteria, Aziz Sancar showed how certain protein molecules - repair enzymes - repair DNA damaged by ultraviolet (UV) light. These discoveries have increased our understanding of how the living cell works, the causes of cancer and ageing processes.

Sancar's DNA model pictured, built in 1986, was used as a working tool as well as in his lectures to explain his discovery. It was later donated to the

Nobel Prize Museum

.

In 2015 Sancar shared the Nobel Prize in Chemistry with Tomas Lindahl and Paul Modrich "for mechanistic studies of DNA repair."