'PCR' originates from English, specifically the phrase 'polymerase chain reaction', formed as an acronym from the initial letters 'P', 'C', and 'R' (the term became common after Kary Mullis developed the technique in 1983).

'polymerase chain reaction' was coined to describe the enzymatic process that links a DNA polymerase with repeated chain-based amplification steps; the abbreviated form 'PCR' entered widespread scientific and public use in the mid-1980s following publication and adoption of the method.

Initially it referred specifically to the laboratory method for amplifying DNA; over time it has also come to mean PCR-based diagnostic tests (colloquially 'a PCR' for 'a PCR test') and has spawned related terms such as 'RT-PCR'.