What types of mutations can be caused by PCR?
What types of mutations can be caused by PCR?
PCR polymerases can introduce different types of mutations, including single-base substitutions, deletions, and insertions. Base substitutions are typically caused by misincorporation of an incorrect dNTP during DNA synthesis.
Polymerases may generate mutations at locations where one or more nucleotides are lost or gained. The frequency of this type of mutation can be sequence dependent, and might be higher in highly repetitive sequences. The most common mutation is a loss of a single nucleotide, which could be a result of template-primer misalignment within a repetitive homopolymeric sequence. DNA rearrangements can also occur when the polymerase terminates synthesis on one DNA strand and continues synthesis after priming occurs on a complementary strand (i.e., strand-switching or jumping PCR). This type of mutation takes place when there is high homology between different regions of DNA. Excessive DNA template in the reaction may also promote this type of mutation.