With all cells depending on DNA as the medium of genetic information, genetic quality control is an essential function of all organisms. DNA replication is an error prone process, and DNA molecules themselves are vulnerable to modification by many metabolic and environmental stressors. Ubiquitous examples include reactive oxygen species, near ultraviolet, and ionizing radiation. Many nucleases participate in DNA repair by recognizing damage sites and cleaving them from the surrounding DNA. These enzymes function independently or in complexes. Most nucleases involved in DNA repair are not sequence-specific. They recognize damage sites through deformation of double stranded DNA (dsDNA) secondary structure.