An American and a Canadian shared the Nobel Prize in chemistry Wednesday for separately discovering how to mass produce DNA and to reprogram the genetic code, techniques with widespread applications in medicine and basic research.
The physics prize was given to two Americans for discovering an unusual pair of orbiting neutron stars that has provided a "revolutionary space laboratory" for tests of Einstein's general theory of relativity.The chemistry Nobel was awarded to Kary B. Mullis, 48, of Xytronyx Inc. of San Diego, and Michael Smith, 61, of the University of British Columbia in Vancouver.
The winners of the physics prize were Russell A. Hulse, 42, and Joseph H. Taylor Jr., 52, both of Princeton University. Each Nobel Prize carries an award of $825,000 and is split among the winners.
Mullis was recognized for his invention in 1985 of a technique called polymerase chain reaction, which allows researchers to produce millions of copies of a single, microscopic strand of DNA within hours.
The technique is being used to diagnose infections, find the causes of hereditary diseases and recover DNA from fossils, as was carried into fiction in the movie "Jurassic Park."
"Now I've got to go out and surf for an hour to wake up and maybe avoid phone calls from journalists for a while," Mullis told the Swedish news agency TT Wednesday morning from his La Jolla, Calif., home.
Smith's technique, called site-directed mutagenesis, allows researchers to alter a single piece of the genetic code in a strand of DNA, reprogramming it to perform differently.
Such mutations allow researchers to determine the functions of the myriad proteins in the human body and to engineer new proteins that could be useful in treating or curing disease.
Smith's and Mullis' techniques were developed independently. Both allow researchers to do vital experiments that would otherwise be impossible.
The winners of the physics prize were honored for the discovery of the first binary pulsar, an orbiting pair of aging, collapsed stars called neutron stars.
The pulsar discovered by Taylor and Hulse provides a laboratory that can be used to test one of Einstein's most daring predictions: that moving objects emit gravitational waves.
In the years since the pulsar was discovered, Hulse and Taylor have made painstaking measurements of the pulsar's bursts. The researchers have determined that the bursts are slowing down. They believe that's because the pulsar has lost energy in the form of gravitational waves.
"So far, Einstein's theory has passed the tests with flying colors," the academy said in its citation.
Hulse and Taylor discovered the binary pulsar in 1974 using the 300-meter radiotelescope at Arecibo, Puerto Rico. Taylor was then at the University of Massachusetts in Amherst and Hulse was his student.
Taylor, reached by AP Network News at home in Princeton, N.J., said: "Well, I'm overwhelmed."
"My big problem is how to spend this day," he told the Swedish news agency TT. "I would like it to be a normal day but I understand it can't be that way," said Taylor, who was about to leave for the university to lecture on the topic "Radio Astronomy and Pulsars."
"What they were doing was patient scholarship, not at all glamorous," said Daniel Kleppner, a professor of physics at the Massachusetts Institute of Technology. "And of course, that's the heart of science."
Novelist Toni Morrison won the literature prize last week, genetic researchers Phillip Sharp and Richard Roberts shared the medicine prize Monday, and economic historians Robert W. Fogel and Douglass C. North won the economics prize Tuesday. Roberts is a British citizen. The other winners are Americans.
The Nobel Peace Prize is to be awarded Friday in Oslo, Norway.