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Dr Kary Mullis

Born
28 December 1944

Kary Mullis is an American biochemist who won the 1993 Nobel Prize in Chemistry for inventing the polymerase chain reaction (PCR) technique. PCR is used to make multiple copies of specific sections of DNA, and is now an indispensable technique in labs across the world and has played a key role in countless fundamental discoveries.


Kary Mullis was born on 28th December 1944 in Lenoir, North Carolina. He studied chemistry at Georgia Institute of Technology, before receiving a PhD in biochemistry from the University of California, Berkeley in 1972.

In 1983, while working as a chemist for the biotechnology company Cetus, Mullis was struck with a brainwave. During his normal drive home from work he came up with an idea for selectively copying a length of DNA billions of times over. This was the basis of the polymerase chain reaction (PCR) procedure which would revolutionise molecular biology over the following decades.

The PCR technique uses molecular markers, called primers, which trigger DNA replication, and a cycle of different temperatures. The technique is crucial in situations where only a small amount of DNA is available and testing cannot be done on it. PCR copies the DNA numerous times to create a large sample that can be used for many situations, including diagnosing diseases, matching criminals to crime scene and identifying bacteria and viruses.

I had solved the most annoying problems in DNA chemistry with a single lightning bolt.

Kary Mullis, Nobel Lecture, 8th December 1993

Mullis and his colleagues at Cetus devoted the following years to developing the PCR procedure. A great advance was the use of an enzyme, a biological catalyst that speeds up reaction, isolated from the bacterium Thermus aquaticus. This bacterium usually lives in hot springs and as such is adapted to withstanding the extreme temperatures of the PCR cycles without changing its structure.

In recognition of the fundamental importance of the PCR technique he had developed, Mullis received both the Nobel Prize for Chemistry and the Japan Prize in 1993. Since then, PCR has been used for an array of applications like sequencing DNA, constructing the evolutionary tree of life, diagnosing and detecting infectious and hereditary diseases and analysing the function of genes.

Since developing PCR, Mullis has been employed by a range of companies as a consultant specialising in nucleic acid chemistry, lectured at various universities and indulged further in his passion for invention. As well as PCR, Mullis also has patents for a UV-sensitive plastic that changes colour in response to light and is currently working on a revolutionary new approach to harnessing the immune system to fight disease more effectively.

In 1998 Mullis’ creative talents were recognised when he was inducted into the National Inventors Hall of Fame.

This profile was written by a Biology: Changing the World volunteer.