Primer dimers form when two primers bind to one another, instead of to the template DNA, due to regions of primer complementarity.
As its name implies, a PD consists of two primer molecules that have attached or (hybridized) to each other because of strings of complementary bases in the primers.
As a result, the DNA polymerase amplifies the PD, leading to competition for PCR reagents, thus potentially inhibiting amplification of the DNA sequence targeted for PCR amplification.
In quantitative PCR, PDs may interfere with accurate quantification.
