Introduction to polymerase chain reaction

The polymerase chain reaction (PCR) has become an indispensable tool of molecular biology (1-5). Since its discovery in 1985 the process has found its integration into all research areas involving the use of DNA and RNA. Using this technique, a small starting sample of DNA or RNA can be used to amplify a specific DNA or RNA target over a million-fold in as little as 2 h. This allows for the detection of as little as a single copy of a gene or part of a gene in cells, whether they be from blood, cultured cells, tissue biopsies, chromosomes, or any other biological system that contains DNA or RNA, including archival materials (formalin-fixed, paraffin-embedded).