Defect in the double stranded deoxyribonucleic acid (DNA) structure in which the DNA double helix contains one (or more) non-standard base pairs.
Note: One mismatch is known as a single mismatch. Multiple mismatches are called multi-base mismatches.
Example: Guanine paired with thymine instead of cytosine, or adenine with cytosine instead of thymine.
Source:
PAC, 2018, 90, 1121. 'Terminology of bioanalytical methods (IUPAC Recommendations 2018)' on page 1145 (https://doi.org/10.1515/pac-2016-1120)