Gapped DNA refers to a type of DNA molecule that has a missing or incomplete section in its strand. It is often used in genetic engineering and molecular biology research. There are several synonyms for gapped DNA, including gapped duplex DNA, gapped duplex oligonucleotide, and nicked DNA. These terms all refer to a DNA strand that has an identifiable discontinuity or gap. In addition, gapped DNA may also be referred to as a DNA lesion or DNA damage, depending on the context in which it is being used. Researchers often use various methods to repair gapped DNA, including ligation, annealing, and polymerase chain reaction (PCR).