The two US-based scientists who shared the Nobel prize in chemistry with a Swedish man for their work on how our cells repair damaged DNA expressed their shock Wednesday over their win.

"My wife picked up the phone and told me the person on the line said this is very important," Aziz Sancar said in a statement issued by the University of North Carolina at Chapel Hill, where he is a professor in the medical school.

"So I took the phone and they told me I won the Nobel Prize. I was very surprised. I had been sleeping; this was 5 am. So I was pretty incoherent. But I thanked them and said, 'It's an incredible honor.'"

"This award means a great deal to me and my lab," said the biochemist, who is Turkish-American. "We've been working hard for many years and I think we've made significant contributions to our field. It's been a great team effort."

Sancar, Sweden's Tomas Lindahl, and Paul Modrich of the United States were awarded the top chemistry award for unravelling the process by which our cells repair mutations caused to DNA by the Sun or carcinogenic substances found in alcohol and cigarettes, for example.

Mistakes in DNA, the chemical code for making and sustaining life, can cause cells to malfunction, age prematurely, and become cancerous.

"With this map, we can now say to a fellow scientist, 'Tell us the gene you're interested in or any spot on the genome, and we'll tell you how it is repaired,'" Sancar said.

Modrich, a professor of biochemistry at the medical school at Duke University, also in North Carolina, was also surprised when the Nobel call came in.

"We're on vacation in New Hampshire, so this was sort of a shock," Modrich said in a statement issued by the school.