Kary Mullis invents the polymerase chain reaction

In 1983 the biochemist Kary Mullis, working for the Cetus Corporation in California, conceived a method for copying a tiny sample of DNA millions of times over using repeated cycles of heating and cooling and a DNA-copying enzyme. Once a heat-stable enzyme from the hot-spring bacterium Thermus aquaticus was used, the process could be automated. PCR became essential in genetics, forensic science, medical diagnosis and virus detection, and was the basis of tests for COVID-19. Mullis shared the 1993 Nobel Prize in Chemistry.

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