Kary Mullis dreamed up PCR on a night drive and got a 10,000 dollar bonus
In 1983, driving through the hills of Mendocino County, a chemist named Kary Mullis worked out how to copy a snippet of DNA over and over. The polymerase chain reaction split biology into before and after and won him a Nobel Prize. His company paid him a 10,000 dollar bonus, then sold the patent for 300 million.
Mullis was born in 1944 in Lenoir, North Carolina, and caught the chemistry bug as a teenager building solid-fuel rockets. His path was erratic. He struggled through his Berkeley doctoral oral exams, and friends helped strip the strangest material out of his dissertation. He then left science to write fiction and spent two years managing a bakery before a friend, Thomas White, coaxed him back and later found him a job at the biotech firm Cetus.
The idea itself was elegant: use two short primers to bracket the stretch of DNA you want, then let a polymerase enzyme copy it again and again, doubling the amount each cycle. Colleagues were sceptical, and White moved Mullis onto the project full-time. He demonstrated it on 16 December 1983, though his results stayed ambiguous for a while, and other Cetus scientists were set to work in parallel. A key fix came in 1986, when Randall Saiki began using a heat-tolerant polymerase from the bacterium Thermus aquaticus, so the enzyme no longer had to be replaced after each hot cycle. That made PCR cheap and automatable.
The method transformed genetics, medicine and forensics, and in 1993 Mullis shared the Nobel Prize in Chemistry. A similar concept, called repair replication, had been described by Har Gobind Khorana and Kjell Kleppe years earlier, but Mullis's repeated heat cycling allowed rapid, exponential copying. When Cetus sold the rights to Roche, Mullis called some former colleagues vultures.
His later reputation was complicated. He was known at Cetus for volatile behaviour, and in later years he downplayed human-caused climate change, doubted that HIV causes AIDS and professed belief in astrology. Skeptical Inquirer cited him as a case of Nobel disease, when laureates speak confidently outside their field. He died in 2019.
Source: Kary Mullis
