How can PCR detect a one-base-pair DNA change?

The polymerase chain reaction (PCR) is a powerful tool in genetic testing that enables the precise identification of genetic variations, including point mutations or single nucleotide polymorphisms that involve a change of only one base pair.12

While PCR is primarily known for amplifying specific segments of DNA, its ability to detect such minute changes is facilitated by the use of specialized DNA probes. These probes are labeled with radioactive isotopes or fluorescent dyes, which allow researchers to identify and visualize the presence or absence of specific sequences. By targeting these precise regions, PCR-based methods can distinguish between healthy genes and those containing single-base-pair alterations, aiding in the diagnosis of various inherited conditions.12