Kary Mullis, the PCR inventor hard at work

Needles in a haystack

PCR is a technique for producing millions of copies of any tiny fragment of genetic information from billions of building blocks. By doing so, it makes them accessible for analysis. Or, to put it in slightly less scientific terms, PCR finds the famous needle in the haystack and copies it until there is a pile of needles big enough to be detected. In 1989, Science Magazine made PCR its “Molecule of the Year.” Roche acquired the global rights to the technology from California-based Cetus Corporation in 1991. Its discoverer, Kary Mullis, was awarded the 1993 Nobel Prize in Chemistry jointly with his colleague Michael Smith. PCR was a genuine stroke of genius that Kary himself liked to describe as the result of chance, naivety and fortunate error.

There are plenty of strange stories about Kary, a passionate surfer as well as a scientist. Many of these are harmless, pointing to his fascination with aliens and UFOs. However, he eventually alienated himself from the scientific world with conspiracy theories about the hole in the ozone layer and AIDS. Nevertheless, it is impossible to overestimate Kary Mullis’s contribution to modern molecular biology, forensics and diagnostics. We as a company would not be what it is today were it not for this stroke of inspiration.

The rights to PCR were purchased at a time when Roche was financially strong and acquisitions and alliances were a key feature of its activities. The major beneficiary was the Diagnostics Division, which grew from modest beginnings in the 1960s to become an international leader. The newly created US-based Roche Molecular Systems announced its arrival with a fanfare in 1992 by launching the Amplicor series of PCR-based tests, the first of which were for chlamydia and HIV-1. These were soon followed by kits to detect other viral, bacterial or fungal infections. At the same time, Rotkreuz-based Roche subsidiary Tegimenta AG developed a fully automatic PCR analyser. This established PCR testing as a routine procedure.

Roche’s entry into PCR-based diagnostics also paved the way for the acquisition of its competitor Boehringer Mannheim in 1997. Together the two companies were able to set new standards, above all for speed and quantitative analysis. Roche’s analytical systems today are not only used in virology (HIV, hepatitis and HPV) and microbiology (fungal infections, MRSA, tuberculosis and herpes), but they are invaluable to the testing of donated blood and in the field of oncology.

Though now a household word, PCR was, until recently, something you’d only hear in a lab. PCR – polymerase chain reaction – is the technology behind the gold standard of coronavirus testing: a rapid and reliable way of detecting the virus that causes COVID-19.

But here’s what happened before anyone knew about it.

This technology will improve our ability to diagnose devastating diseases more quickly and accurately.
Tom MacMahonHead of the Roche Diagnostics group in the USA, talking about PCR in 1991

Molecular diagnostics also opened the door for Roche’s entry into personalised healthcare. For example, PCR-based tests can be used to detect genetic mutations associated with certain forms of skin, colon or lung cancer. Such tests are crucial in helping doctors decide which form of treatment will be most suitable for the patient in question. In some cases, approval for new cancer medicines hinges explicitly on the availability of a companion test. This was first the case with Roche’s medicine Herceptin in 1998.

Recent events have also demonstrated just how reliant modern-day medical diagnostics are on PCR technology. In a matter of weeks after the COVID-19 pandemic outbreak, Roche was able to launch a first PCR test for detecting active SARS-CoV-2 infection. It was given emergency approval by the American regulatory authority in mid-March 2020 and is now in global use as an indispensable aid in combating the COVID-19 pandemic.

Key to personalised healthcare

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