| Kary B. Mullis (1945 - )1993 Nobel Prize in ChemistryB.S.in Chemistry, Georgia Tech;Ph.D. in Biochemistry, University of California-Berkeley. |
The Royal Swedish Academy of Sciences awarded the 1993 Nobel Prize in Chemistry for contributions to the development of methods within DNA-based chemistry, with to Dr. Kary B. Mullis, La Jolla, California, U.S.A., for his invention of the polymerase chain reaction (PCR) method, and to Professor Michael Smith, University of British Columbia, Vancouver, Canada, for his fundamental contributions to the establishment of oligonucleotide-based, site-directed mutagenesis and its development for protein studies.
Polymerase chain reaction (PCR) according to a number of scientists has been the biggest advance in molecular biology in a decade. It is a technique that amplifies DNA, enabling scientists to make millions of copies of a DNA molecule in a very short time. PCR has been used to detect DNA sequences, to diagnose genetic diseases, to carry out DNA fingerprinting, to detect bacteria or viruses (particularly the AIDS virus), and to research human evolution.
Kary Mullis, a scientist and a surfer from La Jolla, California, considered an "intellectual maverick" by many, won a Nobel Prize in Chemistry in 1993 for developing PCR. A native of South Carolina, he received a bachelor's degree in Chemistry from Georgia Tech and a Ph.D. in Biochemistry from U.C. Berkeley. His Ph.D. thesis was entitled, "The Cosmological Significance of Time Reversal," in which he argued that the universe is a balance between matter that is shrinking and matter that is expanding.
After receiving his doctorate, Mullis worked for the Cetus Corporation of Emeryville, CA in the 1970s, during which time he conceived and developed the idea of PCR. The idea was not the product of a painstaking laboratory work, but was conceived while cruising the Pacific Coast Highway from San Francisco to Mendocino on a motorcycle.
"I do my best thinking while driving," the scientist with the tanned face and bleached hair once explained. For this brilliant idea born at the speed of 50 m.p.h., he received $10,000 from Cetus, with whom he eventually parted ways. He now lives in a small apartment across from Windansea Beach, a surfing spot. A man interested in many things in life besides molecular biology and surfing, he has refused to team up with the biotechnology industry or academia. He now consults and lectures around the world about cosmology, mysticism, mathematics, virology, and artificial intelligence.
The chemical methods that Kary B. Mullis developed for studying the DNA molecules of genetic material have further hastened the rapid development of genetic engineering. The methods has greatly stimulated basic biochemical research and opened the way for new applications in medicine and biotechnology.
There are many applications of Mullis' PCR method. It is for example possible using simple equipment to multiply a given DNA segment from a complicated genetic material millions of times in a few hours, which is of very great significance for biochemical and genetic research. The method offers new possibilities particularly in medical diagnostics, and is used, for example, for discovering HIV virus or faulty genes in hereditary diseases. Researchers can also produce DNA from animals that became extinct millions of years ago by using the PCR method on fossil material.
The "Polymerase Chain Reaction" (PCR) technique was first presented as recently as 1985 but is nevertheless already one of the most widespread methods of analysing DNA. With PCR it is possible to replicate several million times, in a test tube, an individual DNA segment of a complicated genetic material. Mullis has described how he got the idea for the PCR during a night drive in the Californian mountains.
Two short oligonucleotides are synthesized so that they are bound correctly
to opposite strands of the DNA segment it is wished to replicate. At the
points of contact an added enzyme (DNA polymerase) can start to read off
the genetic code and link code words through which two new double strands
of DNA are formed. The sample is then heated, which makes the strands separate
so that they can be read off again. The procedure is then repeated time
after time, doubling at each step the number of copies of the desired DNA
segment. Through such repetitive cycles it is possible to obtain millions
of copies of the desired DNA segment within a few hours. The procedure is
very simple, requiring in theory only a test tube and some heat sources,
even though there are now commercial PCR apparati that manage the whole
procedure automatically and with great precision.
The PCR method can be used for reduplicating a segment of a DNA molecule,
e.g. from a blood sample. The procedure is repeated 20-60 times, which can
give millions of DNA copies in a few hours.
The PCR method has decisively improved the outlook for basic research. The sequencing and cloning of genes has been appreciably simplified. PCR has also made Smith's method of site-directed mutagenesis more efficient. Since it is possible with PCR to perform analyses on extremely small amounts of material, it is easy to determine genetic and evolutionary connections between different species. It is very probable that PCR combined with DNA sequencing is going to represent a revolutionary new instrument for studies of the systematics of plant and animal species.