DNA Damage and Repair Assays

DNA repair can be detected by the same assays (alkaline elution and Comet) that are used to detect DNA damage, but with various time intervals between the end of exposure and the time of sampling. An additional assay for assessing DNA repair has been utilized for many years, namely the unscheduled DNA synthesis (UDS) assay. The endpoint measured is the uptake of tritiated thymidine into DNA repair sites following exposure. The sensitivity of the assay is relatively low, especially in vivo, and this limits its predictive value for hazard identification. Thus, a negative response in a UDS assay has very limited value because of this low sensitivity. 

The assessment of DNA repair per se provides rather little information on the quantitative assessment of the potential subsequent mutagenicity of a chemical because it is the frequency of misrepair that is of consequence to the cell with regard 

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Nitrobenzene was nongenotoxic in Salmonella ty-phimurium and mammalian cells in vitro and in mammalian cells in vivo. Studies reported included DNA damage and repair assays, gene mutation assays, chromosomal effects assays, and cell transformation assays. 

Mouse visible or eleetrophoretie specifie-locus tests Assays for skeletal and cataract mutations Cytogenetic analy.sis and heritable translocation assays DNA damage and repair in rodent germ cells Dominant lethal assay... 

Collins, A. R. (2004). The COMET assay for DNA damage and repair. Molecular... 

Assays for DNA Effects DNA damage and repair unscheduled DNA synthesis in vitro / ... 

Olive, P.L., Banath, J.P., and Durand, R.E., Heterogeneity in radiation-induced DNA damage and repair in tumor and normal cells measured using the "comet" assay, Radiat. Res., 122, 86, 1990. 

Snyder, R.D. Matheson, D.W. (1985) Nick translation—a new assay for monitoring DNA damage and repair in cultured human fibroblasts. Environ. Mutag., 1, 267-279... 

J. Laval, S-H. Lu, S. Parodi, A.E. Pegg, and M.F. Rajewsky. DNA damage and repair in mammalian cells, pp. 201-226. In Long-Term and Short-Term Screening Assays for Carcinogens A Critical Appraisal. IARC Monographs. Supplement 2. Lyon International Agency for Research on Cancer, 1980. 

D has been active in many different short-term genetic assays, including DNA damage and repair, mutations in yeast and human cells, sex-linked recessive mutations in fruit flies, and chromosome aberrations in vitro. 

Tice, R.R. (1995) The single cell gel/comet assay a microgel electrophoretic technique for the detection of DNA damage and repair in individual cells. In Environmental Mutagenesis, Philips, D.H. and Venitt, S. (eds), pp. 315-339. Bios Scientific Publishers, Oxford. 

Assays of DNA damage and repair, rather than measuring... 

Collins AR (2004) The comet assay for DNA damage and repair principles, applications, and limitations. Mol Biotecbnol 26(3) 249-261 ECVAM (2012) http //ecvam.jrc.it/consulted. January 2012... 

Fojta M, Danhel A, Havran L, Vyskocil V (2015) Recent progress in electrochemical sensors and assays for DNA damage and repair. Trends Anal Chem. doi 10.1016/j.trac.2015.11.018... 

McNair, F.L., Marples, B., West, C.M.L., and Moore, J.V., A comet assay of DNA damage and repair in K562 cells after photodynamic therapy using hematoporphyrin derivative, methylene blue and meso-tetrahydroxyphenylchlorin, Br. J. Cancer, 75,1721,1997. 

The comet assay consists, particularly, in a valuable and cheap technique since it allows the detection of different cellular answers resulting from DNA damages and repair, which can be observed by the migration, in electrophoresis, of any cellular type obtained from a cell suspension (Sasaki et al., 1997, Mitchelmore and Chipman, 1998). 

DNA repair is a specific response to DNA damage and unlike DNA fragmentation and inhibition cannot be attributed to toxicity ( ). Therefore, DNA repair tests offer an end point of high specificity biologic significance and are recommended in preference to these other assays. 

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