The polymerase chain reaction (PCR) technique, which creates millions of copies of strands of tiny samples of DNA, is now a routine research technique and many labs have a PCR thermal cycler sitting on a bench or in a corner. But back in 1983, when the technique was first discovered, this was an amazing and exciting breakthrough, bringing a step change to biochemistry and molecular biology, and this is all thanks to biochemist Kary Mullis.

Fig 1. Kary Mullis

Kary Mullis was working for the biotech company Cetus (Cetus later merged with Chiron, and was subsequently acquired by Novartis) when he made the PCR breakthrough, in December 1983. As Mullis states in his Nobel prize acceptance speech, he has tinkered with chemicals and in labs since he was eight years old. After a period trying to be a writer in the early 70s after he gained his PhD, he moved back into labs and then joined Cetus in 1979. Mullis started work on oligonucleotides (short strands of genetic material) and began to build up the techniques that would eventually lead to the development of PCR that made his name and his scientific credentials.

Mullis refined the technique in 1986 when he included a heat-stable polymerase, which meant that the enzyme only needed to be added once per experiment, rather than needing to be replaced every cycle, making the process much more affordable. In recognition of his work, Mullis won the Nobel Prize in Chemistry in 1993 for ‘contributions to the developments of methods within DNA-based chemistry’. He shared the prize with Michael Smith, who gained his ‘for his fundamental contributions to the establishment of oligonucleotide-based, site-directed mutagenesis and its development for protein studies’.

From its start in 1983, PCR is now used in medical and biological research, including cloning, genetic analysis, genetic fingerprinting, diagnostics, pathogen detection, and genetic fingerprinting in forensic science and paternity testing.

Suzanne Elvidge is a freelance science, biopharma, business and health writer with more than 20 years of experience. She is editor of Genome Engineering, a blog that monitors the latest developments in genome engineering and that aims to educate (and sometimes to entertain!) and has written for a range of online and print publications including FierceBiomarkers, FierceDrugDelivery, European Life Science, the Journal of Life Sciences (now the Burrill Report), In Vivo, Life Science Leader, Nature Biotechnology, PR Week and Start-Up. She specialises in writing on pharmaceuticals, biotechnology, healthcare, science, lifestyle and green living, but can write on any topic given enough tea and chocolate biscuits. She lives just beyond the neck end of nowhere in the Peak District with her second-hand bookseller husband and two second-hand cats.