• 한국환경성돌연변이발암원학회지
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• 제17권2호
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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.

• Toxicological Research
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• 제23권1호
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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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• 제24권2호
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• pp.93-99
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• 1999

Alkaline single cell gel electrophoresis (SCGE) assay는 일명 혜성분석이라고 부르며 in vivo 와 in vitro 에서 많은 화학적, 생물학적인 인자에 의한 DNA 손상을 감지하는데 유용한 기법으로 각각의 세포에서 DNA 단일 가닥 절단과 알칼리에 약한 장소를 평가하는 새로운 방법으로 인정되고 있다. 단세포 겔 전기영동법 (SCGE)을 사용하여 복숭아씨 추출물이 방사선에 의하여 사람 림프구 DNA에 나타나는 손상을 보호하는 지 여부를 평가하였다. 복숭아씨 추출물로 10 분간 전처리한 림프구를 0, 0.1, 0.3, 0.5, 1.0, 2.0 Gy 의 방사선으로 조사하였고 방사선만을 조사한 림프구 실험군과 비교평가하였다. 혜성분석에서 DNA 가닥 절단에 대한 표식인 tail moment의 증가는 감마선에 대해서 뚜렷한 선량-반응 관계를 나타내었으며 각각의 농도별로 복숭아씨 추출물이 처리된 림프구의 DNA 손상은 현저히 감소하였다. 단세포 겔 전기영동법을 통한 평가결과 복숭아씨 추출물은 방사선에 의한 림프구 DNA 손상에 대한 탁월한 방어효과를 나타내었다.

• 한국환경성돌연변이발암원학회지
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• 제21권2호
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• pp.128-134
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• 2001

Single cell gel electrophoresis (SCGE) assay, also called comet assay, is a rapid and sensitive method to detect DNA damage in single cell level. To evaluate the DNA damage of lymphocytes of pesticides sprayers, SCGE assay was carried out for 50 pesticides sprayer and 58 control subjects. They were interviewed with structured questionnaire to get the information about the kinds and amount of pesticide. Insecticides and fungicides were predominant among pesticides. Major components of pesticides were organophosphorus, organosulfate, cartap, carbamates, and triazole. Sprayed pesticides were classified into two groups. Group I included organophosphorus, organoarsenic, organotin, tetrazine, triazole and gramoxone, which were known to cause DNA damages. Group II pesticide were carbamates, surfactants, organosulfates, etc., which were not found as DNA damaging agents in scientific documents. Olive tail moments of 100 lymphocytes were measured by KOMET 3.1 program for each person. The means of tail moments were compared between farmers exposed to pesticides and control subjects. Farmers showed higher tail moments than control subjects (2.07$\pm$1.40 vs 1.53$\pm$0.77, p<0.05). The means of tail moments also were compared among group I sprayers (n=36), group II sprayers (n=24) and, control subject, and the means or tail moments were 3.4s$\pm$3.2o, 2.66$\pm$2.20 and 1.53$\pm$0.77 respectively. The difference between means of group I sprayers and controls was statistically significant (p<0.05). In conclusion, this study showed higher DNA damage in farmers exposed to pesticides than control subjects, and comet assay could be useful as a biological monitoring method of genotoxic pesticides for farmers.

• Toxicological Research
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• 제22권2호
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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.

• Environmental Analysis Health and Toxicology
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• 제16권1호
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• pp.17-20
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• 2001

The alkaline comet assay, employing a single-cell gel electrophoresis(SCGE), is a rapid, simple and sensitive technique for visualizing and measuring DNA damage leading to strand breakage in individual mammalian cells. The protecting effect of pretreatment with vitamin C and cysteine on the DNA damage of gamma ray was investigated in mice splenic lymphocytes. Vitamin C and cysteine were administered orally for five consecutive days before irradiation. Four week old ICR male mice were irradiated wish 3.5Gy of γ-radiation and were sacrificed 3 days later. Spleens were taken for DNA damage examination by Comet assay and the tail moments of DNA single -strand breaks in tole splenic lymphocytes were evaluated. The results show that pretreatment with vitamin C and cysteine were effective in protecting against DNA damage by gamma ray. Administration of antioxidants like vitamin C and cysteine to mice before irradiation was effective in reducing the tail moment of splenic lymphocytes DNA.

• 대한수의학회지
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• 제44권1호
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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.

• 한국식품과학회지
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• 제31권4호
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• pp.1071-1076
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• 1999

본 연구에서는 김치발효에 관여하는 우세 발효균들의 집락을 분리하고, 발암원인 MNNG에 대하여 이들 분리주들이 갖는 DNA 손상 억제효과를 조사하였다. 이를 위해서 세포의 DNA 손상 및 복구를 측정하는데 이용되는 매우 신속하고 감도가 높은 Single Cell Gel Electrophoresis(SCGE 법, 또는 comet assay)를 사용하였다. 배추김치에서 분리한 3개의 분리주중에서 B-3를 제외한 B-1과 B-2는 양성 대조구와 비교하였을 때 우수한 항유전 독성효과를 나타내었으며(p<0.01), 율무김치의 3 개의 분리주(Y-1, Y-2, Y-3)와 1개의 분리주(Y-4)도 각각 항유전 독성효과를 나타내었다(p<0.05, p<0.01). 총각김치의 5 개 분리주중에서 3개의 분리주와 깍두기의 9개의 분리주중에서 2 개의 분리주들도 각각 항유전 독성효과를 나타내었다(p<0.05, p<0.01).

• Toxicological Research
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• 제29권1호
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• pp.43-52
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• 2013

Zearalenone (ZEN) is a non-steroidal estrogenic mycotoxin produced by several species of Fusarium that are found in cereals and agricultural products. ZEN has been implicated in mycotoxicosis in farm animals and in humans. The toxic effects of ZEN are well known, but the ability of an alkaline Comet assay to assess ZEN-induced oxidative DNA damage in Chang liver cells has not been established. The first aim of this study was to evaluate the Comet assay for the determination of cytotoxicity and extent of DNA damage induced by ZEN toxin, and the second aim was to investigate the ability of N-acetylcysteine amide (NACA) to protect cells from ZEN-induced toxicity. In the Comet assay, DNA damage was assessed by quantifying the tail extent moment (TEM; arbitrary unit) and tail length (TL; arbitrary unit), which are used as indicators of DNA strand breaks in SCGE. The cytotoxic effects of ZEN in Chang liver cells were mediated by inhibition of cell proliferation and induction of oxidative DNA damage. Increasing the concentration of ZEN increased the extent of DNA damage. The extent of DNA migration, and percentage of cells with tails were significantly increased in a concentration-dependent manner following treatment with ZEN toxin (p < 0.05). Treatment with a low concentration of ZEN toxin (25 ${\mu}M$) induced a relatively low level of DNA damage, compared to treatment of cells with a high concentration of ZEN toxin (250 ${\mu}M$). Oxidative DNA damage appeared to be a key determinant of ZEN-induced toxicity in Chang liver cells. Significant reductions in cytolethality and oxidative DNA damage were observed when cells were pretreated with NACA prior to exposure to any concentration of ZEN. Our data suggest that ZEN induces DNA damage in Chang liver cells, and that the antioxidant activity of NACA may contribute to the reduction of ZEN-induced DNA damage and cytotoxicity via elimination of oxidative stress.

• 한국독성학회:학술대회논문집
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• 한국독성학회 2003년도 추계학술대회
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• pp.133-133
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• 2003

In recent years. attention has focused on the application of the alkaline single cell gel electrophoresis (SCGE or Comet) assay in environmental mutagenesis. To evaluate the suitability of the assay as a monitoring. technique, the DNA damages in liver cells and erythrocytes of carp (Cyprinus carpio) exposed to benzo[${\alpha}$]pyrene (B[${\alpha}$]P) were estimated comparatively with the in vivo Comet assay and the micronucleus test (MNT).(omitted)