• Environmental Mutagens and Carcinogens
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• v.17 no.2
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• pp.71-77
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• 1997

The single cell gel electrophoressis(SCGE) assay, also known as the comet assay, is a rapid, simple, visual and sensitive technique for measuring and analysing DNA breakage in mammalian cells. The SCGE or comet assay is a promising test for the detection of DNA damage and repair in individnal cells. It has widespread potential applications in DNA damage and repair studies, genotoxicity testing and biomonitoring. In this microgel electrophoresis technique, cells are embedded in agarose gel on microscope slides, iysed and electrophoresed under alkaline conditions. Cells with increased DNA damage display increased migration of DNA from the nucleus towards the anode. The length of DNA migration indicates the amount of DNA breakage in the cell. The comet assay is also capable of identifying apoptotic cells which contain highly fragmented DNA. Here we review the development of the SCGE assay, existing protocols for the detection and analysis of comets, the relevant underlying principles determining the behaviour of DNA and the potential applications of the technique.

• Proceedings of the Korea Society of Environmental Biology Conference
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• 2003.11a
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• pp.68-73
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• 2003

The possibility of using the alkaline protocol of the single cell gel electrophoresis (SCGE) assay as a method for detecting induced DNA damage has been studied for six major plants. The EMS was applied as a model genotoxic agent on young excised leaves of the tested crops for 18 h at 26$^{\circ}C$ in the dark. With increasing concentrations of 0 to 10 mM EMS, the DNA damage, expressed by the averaged median tail moment values, significantly increased in nuclei of all plants studied. As the results, no correlation between the diameter of nuclei and sensitivity to EMS treatment was observed. The data obtained demonstrate the feasibility of using the SCGE assay for detecting induced DNA damage in plants.

• Toxicological Research
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• v.20 no.3
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• pp.225-232
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• 2004

The suitability of the single cell gel electrophoresis (SCGE) assay as a test for the monitoring of genotoxicity of aquatic environment was evaluated. The SCGE assay was employed to detect DNA damage induced in clam (Spisula sachalinensis) exposed to a direct mutagen, N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) or an indirect mutagen, benzo[a]pyrene (B[a]P). The cells of gill and digestive glands were isolated from clam by homogenization, which was the optimized cell dissociation method, and the level of DNA damage was assessed and expressed as mean tail length. In the gill cells, significant dose- and time-dependent increase was observed in the mean tail length at the concentration from 0.01 to 0.5 ppm MNNG for 96 h. The linear correlation between relative dam-age index (RDI) values was suggested to provide criteria of genotoxicity monitoring for direct acting mutagen. The dose- and time-dependent responses of the digestive glands cells were less sensitive than those of the gill cells. In contrast, the genotoxic response resulting from the exposure of 0.01～1.0 ppm B[a]P to clam revealed a higher sensitivity in the digestive glands cells than the gill cells. The comparison between the time profiles of genotoxic responses in clam and carp, the latter had been obtained in our previous study, indicated that the metabolism of genotoxic compounds in the two aquatic organisms were quite different each other. We conclude that the SCGE assay has the potential as a screening test for routine genotoxicity monitoring of aquatic organisms because of its higher sensitivity and simplicity.

• Toxicological Research
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• v.23 no.1
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• pp.25-31
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• 2007

To evaluate the protective effect of Houttuynia cordata on hydrogen peroxide-induced oxidative DNA damage in HepG2 cell line, we used an alkaline single-cell gel electrophoresis (SCGE; comet assay). The DNA damage was analyzed by tail moment (TM) and tail length (TL), which used markers of DNA strand breaks in SCGE. The $100{\mu}g/ml$ of methanolic extract of Houttuynia cordata root showed significant protective effects (p < 0.01) against hydrogen peroxide-induced DNA damage in HepG2 cells and increased cell viability against hydrogen peroxide. The results of this study indicate that Houttuynia cordata root methanol extract acts as a potential antioxidant, and exhibits potential anticancer properties, which may provide a clue to find applications in new pharmaceuticals for oxidative stability.

• Journal of Radiation Protection and Research
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• v.24 no.2
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• pp.93-99
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• 1999

The alkaline single-cell gel electrophoresis (SCGE) assay, called the comet assay, has been applied to the detection of DNA damage from a number of chemical and biological factors in vivo and in vitro. The comet assay is a novel method to assess DNA single-strand breaks, alkali-labile sites in individual cells. The effect of peach kernel extracts on radiation-induced DNA damage in human blood lymphocytes was evaluated by the SCGE assay. The lymphocytes, with or without pretreatment of the extracts, were exposed to 0, 0.1, 0.3, 0.5, 1.0 and 2.0 Gy of $^{60}Co$ gamma ray. Significantly increased tail moment, which was a marker of DNA strand breaks in the comet assay, showed an excellent dose-response relationship. The treatment of the peach kernel extracts reduced the DNA damage by 30 % in irradiated groups as compared to that in non-treated control groups. The result indicates that the extracts shows radioprotective effect on lymphocyte DNA when assessed by the comet assay.

• Toxicological Research
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• v.22 no.2
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• pp.75-85
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• 2006

This study was designed to evaluate the possible DNA damaging effects of T-2 toxin using an alkaline single cell gel electrophoresis (SCGE) comet assay and also to investigate toxic effects in chickens. A total of 20 chickens were used in these experiments. Graded concentrations of dietary T-2 toxin (0, 4, 8, and $16{\mu}g/g$ of diet) were given to groups of 5 broiler chickens. In comet assay, The DNA damage was analysed by the tail extent moment (TEM) and tail length (TL), which were used as markers of DNA strand breaks in SCGE. A significant dose-dependent increase in the extent of DNA migration as well as in the percentage of cells with tails was observed after treatment with T-2 toxin (P<0.05). Treatment with the low T-2 toxin ($4{\mu}/g$ of diet) induced a relatively low level of DNA damage in comparison with the high T-2 toxin ($16{\mu}/g$ of diet) group. The growth rate was significantly reduced by concentrations of 8, and $16{\mu}/g$ of diet (P < 0.05). The feed conversion ratio were significantly affected by any concentrations (P < 0.05). The relative weight of the spleen, and lung was decreased by the growth inhibitory concentrations. The bursa of Fabricius, thymus, and kid- ney were decreased in relative weight by concentrations of $16{\mu}/g$ of diet. The relative weight of the liver and heart were unaffected. The hemoglobin (Hb), hematocrit (HCT), and mean corpuscular hemoglobin (MCH) were decreased at concentration of $16{\mu}/g$ of diet. As compared with control chickens, there was no marked change in serum components except uric acid in T-2 treated chickens. All lymphoid tissues retained atrophic and lymphoid cell depletion throughout the three weeks trial.

• Korean Journal of Environmental Biology
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• v.29 no.1
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• pp.68-73
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• 2011

The single cell gel electrophoresis (SCGE) assay is a microelectrophoretic technique for assessments of DNA damage at the level of the individual eukaryotic cell. The SCGE assay, due to its simplicity, sensitivity and need of a few cells, has advantages compared to other genomic damage assays such as sister chromatid exchange, chromosomal aberration and micronucleus test. In this study, investigated were the levels of DNA damage and the repair kinetics in the coelomocytes of Eisenia fetida treated with HgCl2 and ionizing radiation by means of the SCGE assay. For detecting DNA damage and repair in coelomocytes, earthworms (E. fetida) were irradiated with six doses of ${\gamma}$-rays (0, 2.5, 5, 10, 20 and 50 Gy) and in vivo exposed to mercuric chloride at 0, 80 and 160 mg $kg^{-1}$ for 48 hours. Then the Olive tail moments were measured during 0~12 hours after irradiation and 0~72 hours after Hg treatment. The results showed that the more the oxidative stress was induced by mercury and radiation, the longer the repair time was required. Also, the results suggest that the SCGE assay may be used as an important tool for comparison of the sensitivity of different species to oxidative stresses.

• The Korea Journal of Herbology
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• v.26 no.2
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• pp.31-37
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• 2011

Objectives : This study was focused to investigate the toxicity of Saussurea lappa (SL) extracts in HL-60 cells and human lymphocytes. We also examined the differentiation effect of SL against leukemia cells. Methods : For examining the toxicity of SL, cytokinesis-block micronucleus (CBMN) assay and single cell gel eletrophoresis (SCGE) assay were used in present study. The cell differentiation effect of SL was evaluated by nitroblue tetrazolium (NBT) reduction assay. Results : The inhibition of cell growth in HL-60 cells was observed in a dose-dependant manner after SL treatment for 24 h. According to SCGE assay, HL-60 cells treated with SL increased DNA damage at $10{\mu}g/m{\ell}$, while DNA damage was induced by 0.1, 1, $10{\mu}g/m{\ell}$ concentration of SL in human lymphocytes. Our results indicated that SL have no genotoxic effect in HL-60 cells and human lymphocytes. Additionally, the differentiation effect was induced in $1{\mu}g/m{\ell}$ SL-treated HL-60 cells. Conclusions : From above results it is suggested that SL could be beneficial for the preparation of the useful agent for treating leukemia.

• Toxicological Research
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• v.17 no.4
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• pp.249-253
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• 2001

Fumonisin B1, a mycotoxin, is thought to induce esophageal cancer in humans and apoptosis in animal cells by inhibiting ceramide synthase. Dumonisin Bl may also generate reactive oxygen species directly or indirectly, leading to DNA damage and lipid peroxidation. In this study, a DNA fragmentation assay, dichlorofluorescein (DCF) analysis, and single cell gel electrophoresis (SCGE) were used to investigate the involvement of cellular free radicals, specifically hydrogen peroxide, in the DNA damaging activity of fumonisin B1. From an in vitro DNA fragmentation assay, E. coli DNA, damage by fumonisin Bl was increased by the addition of superxide dismutase (SOD) and decreased by catalase. SCGE and DCF analysis in vivo showed that the nuclear DNA damage and intracellular free radicals in cultured rat hepatocytes treated with fumonisin B1 were increased with the concentration of fumonisin Bl . DNA damage and free radical generation were inhibited by the addition of catalase. Fumonisin Bl , in the presence of SOD, produces hydrogen peroxide causing oxidative DNA damage and protein malfunction, leading to genotoxicity and cytotoxicity of the toxin.

• Korean Journal of Veterinary Research
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• v.44 no.1
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• pp.41-47
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• 2004

The alkaline single-cell gel electrophoresis (SCGE) assay, called the comet assay, has been applied to detect DNA damage induced by a number of chemicals and biological factors in vivo and in vitro. The DNA damage was analysed by tail moment (TM) and tail length (TL), which were markers of DNA strand breaks in SCGE. Human, mouse and rat peripheral blood lymphocytes (PBLs) were irradiated with different doses of $^{60}Co$ ${\gamma}$-rays, e.g. 1, 2, 4, and 8 Gy at a dose rate of 1 Gy/min. A dose-dependent increase in TM (p<0.01) and TL (p<0.01) was obtained at all the radiation doses (1-8 Gy) in human, mouse and rat PBLs. Mouse PBLs were more sensitive than human PBLs which were in turn more sensitive than rat PBLs when the treated dosages were 1 and 2 Gy. However, human PBLs were more sensitive than mouse PBLs which were in turn more sensitive than rat PBLs when the irradiation dosages were 4 and 8 Gy. Data from all three species could be fitted to a linear-quadratic model. These results indicated that there may be inherent differences in the radio-sensitivity among PBLs of mammalian species.