Mullis, Kary Banks (1944-), an American biochemist, shared the 1993 Nobel Prize in chemistry with Michael Smith of Canada for inventing polymerase chain reaction (PCR), which allowed duplication of a single gene fragment. PCR, a relatively inexpensive technique that mimics nature's way of copying DNA, revolutionized the biotechnology industry and led to significant innovations in law enforcement.
The second of four children, Mullis grew up in Columbia, South Carolina, where his father was a furniture salesman. After his parents separated, his mother supported the family by becoming a real estate agent. Mullis displayed a love of chemicals at an early age and enjoyed playing with a chemistry set. Permitted by his first public high school chemistry teacher to use the lab after school was over for the day, he and his friends experimented with making plastics; Mullis would later invent a plastic that changes color when exposed to ultraviolet light. After high school, he went to the Georgia Institute of Technology on a scholarship. He graduated in 1966 with a degree in chemistry. While there he started his own chemical manufacturing company. In 1972, Mullis earned a doctorate in biochemistry at the University of California, Berkeley. After receiving his degree, Mullis taught at the University of Kansas Medical School and the University of California, San Francisco. He then worked at the Cetus Corporation (now Chiron Corporation), a research company, in Emeryville, California.
The idea for PCR came to Mullis in 1983, not as the result of hours spent in the laboratory but as a result of contemplation during a long automobile drive. Mullis was working at the time as a researcher for Cetus, where his job involved synthesizing nucleotides—short stretches of DNA. As he drove, Mullis was thinking about a new method for identifying nucleotides in DNA fragments. He suddenly realized he had instead thought up a method of finding and multiplying tiny fragments of DNA by mimicking the way in which the enzyme polymerase naturally carries out its job of DNA replication.
In 1987, the Cetus Corporation patented a three-part industrial process for PCR. In the first step, the target genetic material is exposed to heat in order to unwind and separate the strands of its double helix. In the second step, a primer—that is, a single strand consisting of a sequence of a few nucleotides—is attached to a complementary strand of the now single-stranded DNA. In the third step, four types of nucleotides are added, along with ribonucleic acid (RNA) polymerase. Then, similar to the natural process of DNA-copying, a nucleotide chain builds up. By the end of the process, the original two strands of DNA have been replaced by two new double strands, which can themselves be separated by heating, thus reinitiating the process.
The process, which made it possible to take a minute sample of genetic material and duplicate enough of it for study, soon found many uses. Because it allowed the quick identification and amplification of parts of the human genome, it played a major role in the effort to map the human genome. Because it can yield quantities that can be analyzed, it made it easier to detect infectious disease organisms that had been difficult to culture. Because it can easily distinguish among tiny variations in DNA, it has led to new kinds of genetic testing. It has also become an important tool in police investigations, since it can identify the person who left a drop of blood or a single hair at a crime scene. Its usefulness in analyzing prehistoric DNA suggested the plot for Michael Crichton's book and later Steven Spielberg's motion picture Jurassic Park, in which scientists duplicate dinosaur DNA extracted from a mosquito preserved in amber. It may also help scholars piece together thousands of particles of parchment from the Dead Sea Scrolls.
In 1986, Mullis left Cetus. The company paid him only a $10,000 bonus for his invention. Later, DuPont, the multinational pharmaceutical company, sued Cetus over a patent dispute, claiming that a DuPont chemist had actually invented PCR in the 1970's. Cetus had to back Mullis's claim to the invention or risk losing the patent, which proved highly profitable. When pharmaceutical giant Hoffmann-La Roche purchased the patent from Cetus in 1991, it paid Cetus a world-record $300 million.
After working from 1986 to 1988 at Xytronyx, Inc., Mullis became a free-lance consultant. Less than a year after becoming a Nobel laureate, Mullis was banned from speaking at meetings of the European Society for Clinical Investigation, one of Europe's leading medical research bodies, and accused by the society's president of undermining the value of the prize. Before long, it was widely accepted that Mullis is at least one of the most unconventional persons ever to have been awarded the Nobel Prize in chemistry. His 1998 Dancing Naked in the Mind Field, a book of essays, revealed him to be an advocate of astrology and a believer in alien abduction.
Although slated to testify as a forensic expert in the 1995 O. J. Simpson murder case, Mullis was dropped as a witness out of fear the prosecution would discredit him for his admitted use of illegal hallucinogenic drugs. A critic of the science establishment in general, he became notorious for claiming that there is no causal link between HIV and AIDS. He also dismisses as pseudoscientific theories perpetrated by social scientists the ideas that chlorofluorocarbons are destroying the ozone layer and that industrial waste gases are contributing to global warming. In the mid-1990's, he started a company, Star-Gene, to make jewelry, pens, and trading cards incorporating DNA strands of dead celebrities.
In 1998, Mullis was inducted into the National Inventors Hall of Fame for his invention of PCR.
Nash won a scholarship that allowed him to enter the Carnegie Institute of Technology (now Carnegie-Mellon University) in Pittsburgh in 1945. His mathematics professors soon recognized Nash's exceptional ability and convinced him to specialize in mathematics. Nash received a B.A. degree and an M.A. degree in mathematics in 1948. That fall, he entered Princeton University, in Princeton, New Jersey. There he chose to learn not by lecture or book about what was known but by developing his own topics for discourse.
In 1949, while studying for his doctorate, Nash wrote the paper that established the mathematical principles of game theory. He established the principles on a mathematical basis known as the Nash equilibrium. This formula explained the dynamics of conflict between rival sets of interest groups. Game theorists refer to decision-making situations as games and to the decision makers as players. Game theory has become important in such fields as economics, international relations, moral philosophy, political science, social psychology, and sociology.
Nash received his doctorate from Princeton in 1950 and taught at the Massachusetts Institute of Technology (MIT) from 1951 to 1959. Nash began having serious mental disturbances in early 1959. He experienced the symptoms common to people with schizophrenia, a mental disease in which patients often have delusions (false beliefs) and hallucinations (perceptions of things that are not present). Nash required numerous hospital stays. In between bouts of mental illness, he succeeded in his mathematics, working informally at Princeton. Nash slowly improved. At the time of his Nobel award ceremony, in 1994, Nash spoke of his return to rationality.
In 1953, Nash had a son with Eleanor Stier. In 1955, he began dating one of his students, Alicia Larde, and they married in 1957. They had one son who also has a Ph.D. degree in mathematics. Alicia later divorced Nash, though she helped him during his mental troubles and they remarried in June 2001.
Actor Russell Crowe portrayed Nash in the movie, A Beautiful Mind, based on Nash's life. The film was not completely factual, but received critical acclaim and won an Academy Award for the best film of 2001.
Daniel Nathans, an American microbiologist, shared the 1978 Nobel Prize in physiology or medicine with his colleague Hamilton Othanel Smith and with Werner Arber of Switzerland. Nathans was awarded the prize for his analysis of DNA, using a restriction enzyme discovered by Smith as “biochemical scissors.” Restriction enzymes, whose existence was first predicted by Arber, provide the “chemical knives” to cut DNA into defined fragments. By making it possible to separate DNA into its component parts, Nathans's research opened up new paths for solving basic problems in developmental biology and for understanding, preventing, and treating birth defects, hereditary diseases, and cancer.
The youngest of nine children of Russian Jewish immigrant parents, Nathans grew up in poverty during the Depression, and from age 10 began working while going to school. A summa cum laude graduate of the University of Delaware, with distinction in chemistry (1950), he earned his M.D. degree from Washington University School of Medicine in St. Louis, Missouri (1954). Following his internship (1954–1955) and before his residency (1957–1959) at Columbia-Presbyterian Medical Center in New York City, he did research on the biosynthesis of proteins at the National Institutes of Health (1955–1957). An appointment as guest investigator at Rockefeller University in New York followed (1959–1962).
In 1962, he became an assistant professor of microbiology at Johns Hopkins University, where he later served as director of the departments of microbiology and of molecular biology and genetics, and as interim president (1995–1996) of the University's School of Medicine. In 1993, he received the National Medal of Science.
Nathans's discovery of “biochemical scissors,” which led to such biotechnological breakthroughs as the mapping of the human genome and the production of synthetic insulin and growth hormone, earned him the nickname “father of modern biotechnology.”