polymerase chain reaction

Last reviewed 01/2018

The polymerase chain reaction is a means of producing a large amount of DNA quickly. Given that the targetted region of DNA is known, a DNA polymerase enzyme, with its nucleotide substrate, is made to produce this region repeatedly by markers to the site at which it starts and finishes - complimentary oligonucleotide primers.

PCR has been used to:

  • amplify prenatal samples e.g. chorionic villus for cystic fibrosis
  • prepare larger DNA samples for 'fingerprinting' from isolates at crime scenes
  • diagnose infectious disease e.g. meningococcal meningitis
  • screen for malignancy e.g. for predisposing human papilloma virus in those with cervical carcinoma