20th February 2024

Polymerase chain reaction (PCR)

PCR is performed by denaturing the sample DNA and annealing a DNA primer to the denatured DNA to allow expression of the sequence of interest. DNA polymerase is used to amplify the sequence, exponentially increasing the amount of the DNA sequence of interest available. PCR is often only successful in sequences within the hundreds to thousands of base pairs, with sequences over 20kbp almost impossible to amplify.

Gene analysis uses various methods, including electrophoresis, restriction enzyme analysis, allele-specific oligonucleotide hybridisation and multiplex ligation-dependant probe amplification. PCR is versatile, detecting insertions, deletions, point mutations and trinucleotide expansion mutations.