The essential comet assay: A comprehensive guide to measuring DNA damage and repair

Archives of Toxicology

Volumn 87, Issue 6, 2013, Pages 949-968

  Azqueta, Amaya ^a   Collins, Andrew R ^b  

^a UNIVERSITY OF NAVARRA   (Spain)

^b UNIVERSITY OF OSLO   (Norway)

Author keywords

Biomonitoring; Comet assay; DNA damage; DNA repair; Ecogenotoxicology; Genotoxicity

Indexed keywords

4 NITROQUINOLINE 1 OXIDE; ALPHA TOCOPHEROL; ASCORBIC ACID; BENZO[A]PYRENE; BETA CAROTENE; CYCLOPHOSPHAMIDE; DNA; DNA (APURINIC OR APYRIMIDINIC SITE) LYASE; DNA FORMAMIDOPYRIMIDINE GLYCOSYLASE; EDETIC ACID; ETOPOSIDE; FLUOMETURON; HYDROGEN PEROXIDE; MANNITOL; MESYLIC ACID METHYL ESTER; METHYLATED DNA PROTEIN CYSTEINE METHYLTRANSFERASE; METHYLNITROSOUREA; MITOCHONDRIAL DNA; TRITON X 100; URACIL DNA GLYCOSIDASE;

ACCURACY; CALIBRATION; CELL VIABILITY; COMET ASSAY; CYTOTOXICITY; DNA DAMAGE; DNA FRAGMENTATION; DNA METHYLATION; DNA REPAIR; DNA SUPERCOILING; DOUBLE STRANDED DNA BREAK; DRUG EFFICACY; EXCISION REPAIR; FLUORESCENCE IN SITU HYBRIDIZATION; GENOTOXICITY; HIGH PERFORMANCE LIQUID CHROMATOGRAPHY; HUMAN; IONIZING RADIATION; MASS FRAGMENTOGRAPHY; MGMT GENE; NONHUMAN; PERIPHERAL BLOOD MONONUCLEAR CELL; PRIORITY JOURNAL; REVIEW; SINGLE DRUG DOSE; SINGLE STRANDED DNA BREAK; STANDARD;

ANIMALS; CELL SURVIVAL; COMET ASSAY; DNA DAMAGE; DNA METHYLATION; DNA REPAIR; DOSE-RESPONSE RELATIONSHIP, DRUG; ENVIRONMENTAL MONITORING; GENETIC MARKERS; HIGH-THROUGHPUT SCREENING ASSAYS; HUMANS; MICROSCOPY, FLUORESCENCE; REPRODUCIBILITY OF RESULTS; RISK ASSESSMENT;

EUKARYOTA;

EID: 84878682176     PISSN: 03405761     EISSN: 14320738     Source Type: Journal    
DOI: 10.1007/s00204-013-1070-0     Document Type: Review

References (104)

1. Ahnström G, Erixon K (1981) Measurement of strand breaks by alkaline denaturation and hydroxyapatite chromatography. In: Friedberg EC, Hanawalt PC (eds) DNA Repair. A Laboratory Manual of Research Procedures. Marcel Dekker, New York, pp 403-418
2. Alapetite C, Thirion P, de la Rochefordière A, Cosset J-M, Moustacchi E (1999) Analysis by alkaline comet assay of cancer patients with severe reactions to radiotherapy: defective rejoining of radioinduced DNA strand breaks in lymphocytes of breast cancer patients. Int J Cancer 83:83-90
3. Al-Salmani K, Abbas HHK, Schulpen S, Karbaschi M, Abdalla I, Bowman KJ, So KK, Evans MD, Jones GDD, Godschalk RW, Cooke MS (2011) Simplified method for the collection, storage, and comet assay analysis of DNA damage in whole blood. Free Rad Biol Med 51:719-725
4. Arendt B, Ellinger S, Kekic K, Geus L, Fimmers R, Spengler U, Muller WU, Goerlich R (2005) Single and repeated moderate consumption of native or dealcoholized red wine show different effects on antioxidant parameters in blood and DNA strand breaks in peripheral leukocytes in healthy volunteers: a randomized controlled trial [ISRCTN68505294]. Nutr J 4:33
5. Azqueta A, Gutzkow KB, Brunborg G, Collins AR (2011a) Towards a more reliable comet assay; Optimising agarose concentration, unwinding time and electrophoresis conditions. Mutat Res 724:41-45
6. Azqueta A, Meier S, Priestley C, Gutzkow KB, Brunborg G, Sallette J, Soussaline F, Collins A (2011b) The influence of scoring method on variability in results obtained with the comet assay. Mutagenesis 26:393-399
7. Azqueta A, Gutzkow KB, Priestley CC, Meier S, Walker JS, Brunborg G, Collins A (2013a) A comparative performance test of standard, medium- and high-throughput comet assays. Toxicol in Vitro 27:768-773
8. Azqueta A, Arbillaga L, Lopez de Cerain A, Collins A (2013b) Enhancing the sensitivity of the comet assay as a genotoxicity test, by combining it with bacterial repair enzyme FPG. Mutagenesis 28:271-277
9. Berdal KG, Johansen RF, Seeberg E (1998) Release of normal bases from intact DNA by a native DNA repair enzyme. EMBO J 17:363-367
10. Bohr VA, Smith CA, Okumoto DS, Hanawalt PC (1985) DNA repair in an active gene: removal of pyrimidine dimers from the DHFR gene of CHO cells is much more efficient than in the genome overall. Cell 40:359-369
11. Bonassi S, Znaor A, Ceppi M, Lando C, Chang WP, Holland N, Kirsch-Volders M, Zeiger E, Ban S, Barale R, Bigatti MP, Bolognesi C, Cebulska-Wasilewska A, Fabianova E, Fucic A, Hagmar L, Joksic G, Martelli A, Migliore L, Mirkova E, Scarfi MR, Zijno A, Norppa H, Fenech M (2007) An increased micronucleus frequency in peripheral blood lymphocytes predicts the risk of cancer in humans. Carcinogenesis 28:625-631
12. Boyle SP, Dobson VL, Duthie SJ, Kyle JAM, Collins AR (2000) Absorption and DNA protective effects of flavonoid glycosides from an onion meal. Eur J Nutr 39:213-223
13. Bradley MO, Kohn KW (1979) X-ray induced DNA double strand break production and repair in mammalian cells as measured by neutral filter elution. Nucl Acids Res 7:793-804
14. Bräuner EV, Forchhammer L, Moller P, Simonsen J, Glasius M, Wahlin P, Raaschou-Nielsen O, Loft S (2007) Exposure to ultrafine particles from ambient air and oxidative stress-induced DNA damage. Env Health Persp 115:1177-1182
15. Brendler-Schwaab SY, Schmezer P, Liegibel U, Weber S, Michalek K, Tompa A, Pool-Zobel BL (1994) Cells of different tissues for in vitro and in vivo studies in toxicology: compilation of isolation methods. Toxicol In Vitro 8:1285-1302
16. Burlinson B (2012) The in vitro and in vivo comet assays. In: Parry JM, Parry EM (eds) Genetic toxicology: principles and methods, pp 143-163
17. Collins AR, Azqueta A (2012a) Single-cell gel electrophoresis combined with lesion-specific enzymes to measure oxidative damage to DNA. Meth Cell Biol 112:69-92
18. Collins AR, Azqueta A (2012b) DNA repair as a biomarker in human biomonitoring studies; further applications of the comet assay. Mutat Res 736:122-129
19. Collins AR, Horvathova E (2001) Oxidative DNA damage, antioxidants and DNA repair; applications of the comet assay. Biochem Soc Trans 29:337-341
20. Collins AR, Duthie SJ, Dobson VL (1993) Direct enzymic detection of endogenous oxidative base damage in human lymphocyte DNA. Carcinogenesis 14:1733-1735
21. Collins A, Cadet J, Epe B, Gedik C (1997a) Problems in the measurement of 8-oxoguanine in human DNA. Report of a workshop, DNA Oxidation, held in Aberdeen, UK, 19-21 January, 1997. Carcinogenesis 18:1833-1836
22. Collins AR, Mitchell DL, Zunino A, de Wit J, Busch D (1997b) UV-sensitive rodent mutant cell lines of complementation groups 6 and 8 differ phenotypically from their human counterparts. Environ Mol Mutagen 29:152-160
23. Collins AR, Dobson VL, Dusinská M, Kennedy G, Stetina R (1997c) The comet assay: what can it really tell us? Mutat Res 375:183-193
24. Collins AR, Olmedilla B, Southon S, Granado F, Duthie SJ (1998) Serum carotenoids and oxidative DNA damage in human lymphocytes. Carcinogenesis 19:2159-2162
25. Collins AR, Dusinska M, Horska A (2001a) Detection of alkylation damage in human lymphocyte DNA with the comet assay. Acta Biochim Polon 48:611-614
26. Collins AR, Dusinska M, Horvathova E, Munro E, Savio M, Stetina R (2001b) Inter-individual differences in DNA base excision repair activity measured in vitro with the comet assay. Mutagenesis 16:297-301
27. Collins BH, Horska A, Hotten PM, Riddoch C, Collins AR (2001c) Kiwifruit protects against oxidative DNA damage in human cells and in vitro. Nutr Cancer 39:148-153
28. Collins AR, Harrington V, Drew J, Melvin R (2003) Nutritional modulation of DNA repair in a human intervention study. Carcinogenesis 24:511-515
29. Collins AR, Azqueta Oscoz A, Brunborg G, Gaivão I, Giovannelli L, Kruszewski M, Smith CC, Stetina R (2008) The comet assay: topical issues. Mutagenesis 23:143-151
30. Collins A, Anderson D, Coskun E, Dhawan A, Dusinska M, Koppen G, Kruszewski M, Moretti M, Rojas E, Speit G, Valverde M, Bonassi S (2012) Launch of the ComNet (comet network) project on the comet assay in human population studies during the International Comet Assay Workshop meeting in Kusadasi, Turkey (September 13-16, 2011). Mutagenesis 27:385-386
31. Cook PR (1999) The organization of replication and transcription. Science 284:1790-1795
32. Cook PR, Brazell IA, Jost E (1976) Characterization of nuclear structures containing superhelical DNA. J Cell Sci 22:303-324
33. Cortés-Gutiérrez EI, Dávila-Rodríguez MI, Fernández JL, López-Fernández C, Gosálbez A, Gosálvez J (2011) New application of the comet assay: chromosomeGÇôComet assay. J Histochem Cytochem 59:655-660
34. Danielsen PH, Bräuner EV, Barregard L, Sällsten G, Wallin M, Olinski R, Rozalski R, Møller P, Loft S (2008) Oxidatively damaged DNA and its repair after experimental exposure to wood smoke in healthy humans. Mutat Res 642:37-42
35. Dusinska M, Collins A (1996) Detection of oxidised purines and UV-induced photoproducts in DNA of single cells, by inclusion of lesion-specific enzymes in the comet assay. Alt Lab Animals 24:405-411
36. Dusinska M, Collins AR (2008) The comet assay in human biomonitoring: gene environment interactions. Mutagenesis 23:191-205
37. Dusinska M, Dzupinkova Z, Wsolova L, Harrington V, Collins AR (2006) Possible involvement of XPA in repair of oxidative DNA damage deduced from analysis of damage, repair and genotype in a human population study. Mutagenesis 21:205-211
38. Duthie SJ, McMillan P (1997) Uracil misincorporation in human DNA detected using single cell gel electrophoresis. Carcinogenesis 18:1709-1714
39. Duthie SJ, Ma A, Ross MA, Collins AR (1996) Antioxidant supplementation decreases oxidative DNA damage in human lymphocytes. Cancer Res 56:1291-1295
40. EFSA Scientific Committee (2011) Scientific opinion on genotoxicity testing strategies applicable to food and feed safety assessment. EFSA J 9:2379. doi: 10.2903/j.efsa.2011.2379
41. Ersson C, Möller L (2011) The effects on DNA migration of altering parameters in the comet assay protocol such as agarose density, electrophoresis conditions and durations of the enzyme or the alkaline treatments. Mutagenesis 26:689-695
42. Ersson C, Møller P, Forchhammer L, Loft S, Azqueta A, Godschalk RWL, van Schooten F-J, Jones GDD, Higgins JA, Cooke MS, Mistry V, Karbaschi M, Phillips DH, Sozeri O, Routledge MN, Nelson-Smith K, Riso P, Porrini M, Matullo G, Allione A, Stȩpnik M, Ferlińska M, Teixeira JP, Costa S, Corcuera L-A, López de Cerain A, Laffon B, Valdiglesias V, Collins AR, Möller L (2013) An ECVAG inter-laboratory validation study of the comet assay: inter- and intra-laboratory variation of DNA strand breaks and FPG-sensitive sites in human mononuclear cells. Mutagenesis 28:279-286
43. ESCODD (2002a) Comparative analysis of baseline 8-oxo-7,8-dihydroguanine in mammalian cell DNA, by different methods in different laboratories: an approach to consensus. Carcinogenesis 23:2129-2133
44. ESCODD (2002b) Inter-laboratory validation of procedures for measuring 8-oxo-7,8-dihydroguanine/8-oxo-7,8-dihydro-2′-deoxyguanosine in DNA. Free Rad Res 36:239-245
45. ESCODD (2003) Measurement of DNA oxidation in human cells by chromatographic and enzymic methods. Free Rad Biol Med 34:1089-1099
46. ESCODD, Gedik CM, Collins A (2005) Establishing the background level of base oxidation in human lymphocyte DNA: results of an interlaboratory validation study. FASEB J 19:82-84
47. Feinberg AP, Vogelstein B (1983) Hypomethylation distinguishes genes of some human cancers from their normal counterparts. Nature 301:89-92
48. Forchhammer L, Johansson C, Loft S, Möller L, Godschalk RWL, Langie S, Jones GDD, Kwok RWL, Collins AR, Azqueta A, Phillips DH, Sozeri O, Stepnik M, Palus J, Vogel U, Wallin H, Routledge MN, Handforth C, Allione A, Matullo G, Teixeira JP, Costa S, Riso P, Porrini M, Møller P (2010) Variation in the measurement of DNA damage by comet assay measured by the ECVAG inter-laboratory validation trial. Mutagenesis 25:113-123
49. Forchhammer L, Ersson C, Loft S, Möller L, Godschalk RWL, van Schooten FJ, Jones GDD, Higgins JA, Cooke M, Mistry V, Karbaschi M, Collins AR, Azqueta A, Phillips DH, Sozeri O, Routledge MN, Nelson-Smith K, Riso P, Porrini M, Matullo G, Allione A, Stepnik M, Komorowska M, Teixeira JP, Costa S, Corcuera LA, Lopez de Cerain A, Laffon B, Valdiglesias V, Møller P (2012) Inter-laboratory variation in DNA damage using a standard comet assay protocol. Mutagenesis 27:665-672
50. Gaivão I, Piasek A, Brevik A, Shaposhnikov S, Collins AR (2009) Comet assay-based methods for measuring DNA repair in vitro; estimates of inter- and intra-individual variation. Cell Biol Toxicol 25:45-52
51. Gichner T, Znidar I, Wagner ED, Plewa MJ (2009) The use of higher plants in the comet assay. In: Anderson D, Dhawan A (eds) The comet assay in toxicology. Royal Society of Chemistry, London, pp 98-119
52. Glei M, Hovhannisyan G, Pool-Zobel BL (2009) Use of comet-FISH in the study of DNA damage and repair: review. Mutat Res 681:33-43
53. Green MHL, Lowe JE, Waugh APW, Aldridge KE (1994) Effect of diet and vitamin C on DNA strand breakage in freshly-isolated human white blood cells. Mutat Res 316:91-102
54. Gutzkow KB, Langleite TM, Meier S, Graupner A, Collins A, Brunborg G (2013) High throughput comet assay using 96 minigels. Mutagenesis 28:333-340
55. Hagmar L, Bonassi S, Stromberg U, Brogger A, Knudsen LE, Norppa H, Reuterwall C (1998) Chromosomal aberrations in lymphocytes predict human cancer: a report from the European Study Group on Cytogenetic Biomarkers and Health (ESCH). Cancer Res 58:4117-4121
56. Hartmann A, Agurell E, Beevers C, Brendler-Schwaab S, Burlinson B, Clay P, Collins A, Smith A, Speit G, Thybaud V, Tice RR (2003) Recommendations for conducting the in vivo alkaline Comet assay. Mutagenesis 18:45-51
57. Ho CK, Choi SW, Siu PM, Benzie IFF (2011) Cryopreservation and storage effects on cell numbers and DNA damage in human lymphocytes. Biopres Biobank 9:343-347
58. Hoelzl C, Knasmüller S, Misik M, Collins A, Dusinska M, Nersesyan A (2009) Use of single cell gel electrophoresis assays for the detection of DNA-protective effects of dietary factors in humans: recent results and trends. Mutat Res 681:68-79
59. Horvathova E, Dusinska M, Shaposhnikov S, Collins AR (2004) DNA damage and repair measured in different genomic regions using the comet assay with fluorescent in situ hybridization. Mutagenesis 19:269-276
60. Hughes CM, Lewis SEM, McKelvey-Martin VJ, Thompson W (1996) A comparison of baseline and induced DNA damage in human spermatozoa from fertile and infertile men, using a modified comet assay. Molec Human Repro 2:613-619
61. ICH harmonised tripartite guideline S2 (R1). Guidance on genotoxicity testing and data interpretation for pharmaceuticals intended for human use. http://www.ich.org/products/guidelines/safety/article/safety-guidelines.html. 2011. International Conference on Harmonisation of Technical Requirements for Registration of Pharmaceuticals for Human Use
62. Jha AN (2008) Ecotoxicological applications and significance of the comet assay. Mutagenesis 23:207-221
63. Johansson C, Møller P, Forchhammer L, Loft S, Godschalk RWL, Langie SAS, Lumeij S, Jones GDD, Kwok RWL, Azqueta A, Phillips DH, Sozeri O, Routledge MN, Charlton AJ, Riso P, Porrini M, Allione A, Matullo G, Palus J, Stepnik M, Collins AR, Möller L (2010) An ECVAG trial on assessment of oxidative damage to DNA measured by the comet assay. Mutagenesis 25:125-132
64. Kirkland D (2011) Improvements in the reliability of in vitro genotoxicity testing. Expert Opin Drug Metab Toxicol 7:1513-1520
65. Kirkland D, Speit G (2008) Evaluation of the ability of a battery of three in vitro genotoxicity tests to discriminate rodent carcinogens and non-carcinogens: III. Appropriate follow-up testing in vivo. Mutat Res 654:114-132
66. Kumaravel TS, Jha AN (2006) Reliable comet assay measurements for detecting DNA damage induced by ionising radiation and chemicals. Mutat Res 605:7-16
67. Langie SAS, Knaapen AM, Brauers KJJ, van Berlo D, van Schooten F-J, Godschalk RWL (2006) Development and validation of a modified comet assay to phenotypically assess nucleotide excision repair. Mutagenesis 21:153-158
68. Langie SAS, Wilms LC, Hämäläinen S, Kleinjans JCS, Godschalk RWL, van Schooten FJ (2010) Modulation of nucleotide excision repair in human lymphocytes by genetic and dietary factors. Br J Nutr 103:490-501
69. Li Q, Laval J, Ludlum DB (1997) FPG protein releases a ring-opened N-7 guanine adduct from DNA that has been modified by sulfur mustard. Carcinogenesis 18:1035-1038
70. Lindahl T, Wood RD (1999) Quality control by DNA repair. Science 286:1897-1905
71. Lorenzo Y, Azqueta A, Luna L, Bonilla F, Dominguez G, Collins AR (2009) The carotenoid b-cryptoxanthin stimulates the repair of DNA oxidation damage in addition to acting as an antioxidant in human cells. Carcinogenesis 30:308-314
72. Lorenzo Y, Costa S, Collins AR, Azqueta A (2013) The comet assay, DNA damage, DNA repair and cytotoxicity: hedgehogs are not always dead. Mutagenesis. doi: 10.1093/mutage/get018
73. Lovell DP (2009) Statistical analysis of comet assay data. In: Anderson D, Dhawan A (eds) The comet assay in toxicology. Royal Society of Chemistry, London, pp 424-450
74. Lovell DP, Omori T (2008) Statistical issues in the use of the comet assay. Mutagenesis 23:171-182
75. McKenna DJ, Rajab NF, McKeown SR, McKerr G, McKelvey-Martin VJ (2003) Use of the comet-FISH assay to demonstrate repair of the TP53 gene region in two human bladder carcinoma cell lines. Radiat Res 159:49-56
76. McNamee JP, McLean JRN, Ferrarotto CL, Bellier PV (2000) Comet assay: rapid processing of multiple samples. Mutat Res 466:63-69
77. Mercey E, Obeïd P, Glaise D, Calvo-Muñoz ML, Guguen-Guillouzo C, Fouqué B (2010) The application of 3D micropatterning of agarose substrate for cell culture and in situ comet assays. Biomaterials 31:3156-3165
78. Olive PL, Frazer G, Banath JP (1993) Radiation-induced apoptosis measured in TK6 human B lymphoblast cells using the comet assay. Rad Res 136:130-136
79. Oliveira R, Johansson B (2012) Quantitative DNA damage and repair measurement with the yeast comet assay. In: Bjergbæk L (ed) DNA repair protocols, Meth Mol Biol 920. Humana Press, New York, pp 101-109
80. Osnes-Ringen Ø, Azqueta AO, Moe MC, Zetterström C, Röger M, Nicolaissen B, Collins AR (2012) DNA damage in lens epithelium of cataract patients in vivo and ex vivo. Acta Ophthalm. doi: 10.1111/j.1755-3768.2012. 02500.x [Epub ahead of print]
81. Ostling O, Johanson KJ (1984) Microelectrophoretic study of radiation-induced DNA damages in individual mammalian cells. Biochem Biophys Res Commun 123:291-298
82. Panayiotidis M, Collins AR (1997) Ex vivo assessment of lymphocyte antioxidant status using the comet assay. Free Rad Res 27:533-537
83. Pourrut B, Séverine J, Silvestre J, Pinelli E (2011) Lead-induced DNA damage in Vicia faba root cells: potential involvement of oxidative stress. Mut Res Genet Toxicol Environ Mutagen 726:123-128
84. Rapp A, Bock C, Dittmar H, Greulich K-O (2000) UV-A breakage sensitivity of human chromosomes as measured by COMET-FISH depends on gene density and not on the chromosome size. J Photochem Photobiol B Biol 56:109-117
85. Rojas E, Valverde M, Lopez MC, Naufal I, Sanchez I, Bizarro P, Lopez I, Fortoul TI, Ostrosky-Wegman P (2000) Evaluation of DNA damage in exfoliated tear duct epithelial cells from individuals exposed to air pollution assessed by single cell gel electrophoresis assay. Mutat Res 468:11-17
86. Ryk C, Routledge MN, Allan JM, Wild CP, Kumar R, Lambert B, Hou S (2008) Influence of DNA repair gene polymorphisms on the initial repair of MMS-induced DNA damage in human lymphocytes as measured by the alkaline comet assay. Environ Mol Mutagen 49:669-675
87. Santos SJ, Singh NP, Natarajan AT (1997) Fluorescence in situ hybridization with comets. Exp Cell Res 232:407-411
88. Sasaki YF, Izumiyama F, Nishidate E, Ohta T, Ono T, Matsusaka N, Tsuda S (1997) Simple detection of in vivo genotoxicity of pyrimethamine in rodents by the modified alkaline single-cell gel electrophoresis assay. Mutat Res 392:251-259
89. Shaposhnikov S, Larsson C, Henriksson S, Collins A, Nilsson M (2006) Detection of Alu sequences and mtDNA in comets using padlock probes. Mutagenesis 21:243-247
90. Shaposhnikov S, Frengen E, Collins AR (2009) Increasing the resolution of the comet assay using fluorescent in situ hybridization: a review. Mutagenesis 24:383-389
91. Shaposhnikov S, Azqueta A, Henriksson S, Meier S, Gaivão I, Huskisson NH, Smart A, Brunborg G, Nilsson M, Collins AR (2010) Twelve-gel slide format optimised for comet assay and fluorescent in situ hybridisation. Toxicol Lett 195:31-34
92. Singh NP, McCoy MT, Tice RR, Schneider EL (1988) A simple technique for quantitation of low levels of DNA damage in individual cells. Exp Cell Res 175:184-191
93. Slyskova J, Dusinska M, Kuricova M, Soucek P, Vodickova L, Susova S, Naccarati A, Tulupova E, Vodicka P (2007) Relationship between the capacity to repair 8-oxoguanine, biomarkers of genotoxicity and individual susceptibility in styrene-exposed workers. Mut Res Genet Toxicol Environ Mutagen 634:101-111
94. Smith CC, O'Donovan MR, Martin EA (2006) hOGG1 recognizes oxidative damage using the comet assay with greater specificity than FPG or ENDOIII. Mutagenesis 21:185-190
95. Spanswick V, Hartley J, Hartley J (2010) Measurement of DNA interstrand crosslinking in individual cells using the single cell gel electrophoresis (Comet) assay. In: Fox Keith R (ed) Drug-DNA interaction protocols, Meth Mol Biol 613. Humana Press, London, pp 267-282
96. Speit G, Schütz P, Bonzheim I, Trenz K, Hoffmann H (2004) Sensitivity of the FPG protein towards alkylation damage in the comet assay. Toxicol Lett 146:151-158
97. Stang A, Witte I (2009) Performance of the comet assay in a high-throughput version. Mutat Res 675:5-10
98. Szeto YT, Benzie IFF, Collins AR, Choi SW, Cheng CY, Yow CMN, Tse MMY (2005) A buccal cell model comet assay: development and evaluation for human biomonitoring and nutritional studies. Mutat Res 578:371-381
99. Tice RR, Agurell E, Anderson D, Burlinson B, Hartmann A, Kobayashi H, Miyamae Y, Rojas E, Ryu JC, Sasaki YF (2000) Single cell gel/comet assay: guidelines for in vitro and in vivo genetic toxicology testing. Environ Mol Mutagen 35:206-221
100. Uhl M, Helma C, Knasmüller S (1999) Single-cell gel electrophoresis assays with human-derived hepatoma (Hep G2) cells. Mutat Res 441:215-224
101. Valverde M, Rojas E (2009) Environmental and occupational biomonitoring using the comet assay. Mutat Res 681:93-109
102. Wasson GR, McGlynn AP, McNulty H, O'Reilly SL, McKelvey-Martin VJ, McKerr G, Strain JJ, Scott J, Downes CS (2006) Global DNA and p53 region-specific hypomethylation in human colonic cells is induced by folate depletion and reversed by folate supplementation. J Nutr 136:2748-2753
103. Wentzel JF, Gouws C, Huysamen C, Ev Dyk, Koekemoer G, Pretorius PJ (2010) Assessing the DNA methylation status of single cells with the comet assay. Anal Biochem 400:190-194
104. Wood DK, Weingeist DM, Bhatia SN, Engelward BP (2010) Single cell trapping and DNA damage analysis using microwell arrays. Proc Natl Acad Sci 107:10008-10013