• Journal of Environmental Science International
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• v.14 no.11
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• pp.1071-1079
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• 2005

Using single cell gel electrophoresis, DNA single strand breaks were determined in various marine organisms. DNA damage on fish blood cells was detected to know whether there was a difference between Incheon, Pohang, Masan, and Tongyeong as a control site. Tongyeong showed the lowest DNA damage among the study areas. Mussels, transplanted to Masan Bay for one month, revealed high DNA damage at sites with high economical activity. In two weeks exposure of polychaete to Incheon sediments, higher DNA damage was detected in the sediment adjacent to Incheon harbor than open sea. These results suggested that the marine organism from the polluted area revealed a relatively high DNA damage. In addition, these areas might be contaminated with genotoxic compounds and comet assay was useful as a bioassay to detect DNA damage in marine organisms.

• CELLMED
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• v.3 no.3
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• pp.22.1-22.10
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• 2013

Traditional Chinese medicine (TCM) in single herb or formula prescription has been used for thousands of years. Many of them possess antioxidant activity and the activity may contribute the therapeutic effect. This paper would review the relationship of traditional herbal medicine and antioxidant with particular reference to ginseng. This medicinal herb has been used worldwide with extensive tonic effect. The comet assay, a technique for DNA protecting and damaging investigation would be introduced and the application of comet assay on TCM would be discussed.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.36 no.4
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• pp.346-351
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• 2003

Single-cell gel electrophoresis (comet assay) was used to detect DNA single strand break in blood cells from several marine fish species. Three fish species were collected from Georgia coastal area. Mummichog, Fundulus heteroclitus showed higher DNA damage than sea bass, Lateolabrax japonicus and trout, Oncorhynchus masou masou under the same experimental conditions. Mummichogs had more alkaline-labile sites on their DNA than other fish species. The comet assay with mummichog blood cells at pH 12.5 showed a dose-response curve with the increasing concentrations of hydrogen peroxide. While the isolated leucocytes showed no increase of DNA damage after in vitro exposure to 2-methyl-1,4-naphthoquinone (MNQ), erythrocytes showed dose-dependent DNA damage. These results indicate that the comet assay can be applied successfully as a bioassay using erythrocyte for environmental monitoring.

• Proceedings of the Korean Society for Food Science of Animal Resources Conference
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• 2005.10a
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• pp.153-156
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• 2005

방사선 조사한 쇠고기와 돼지고기는 방사선 조사 선량이 증가함에 따라 comet tail이 증가하나 유의적으로 증가하지는 않는다. 그러나 방사선 조사한 돼지고기에서 3 kGy를 제외한 다른 조사선량과 대조구는 저장기간이 지남에 따라 comet tail이 유의적으로 증가하였다. 반면에 방사선 조사한 토끼고기는 방사선 조사 선량이 증가함에 따라 comet tail이 유의적으로 증가하나 저장기간에 대해서는 대조구를 제외하고 유의차가 없었다.

• The Bulletin of The Korean Astronomical Society
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• v.41 no.1
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• pp.81.4-82
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• 2016

Recent analysis on asteroidal thermophysical property revealed that there is a tendency that their thermal inertia decrease with their sizes at least for main belt asteroids. However, little is known about the thermal properties of comet-like bodies. In this work we utilized a simple thermophysical model to calculate the thermal inertia of a bare nucleus of comet P/2006 HR30 (Siding Spring) and an asteroid in comet-like orbit 4015 Wilson-Harrington from AKARI observation data. It is also shown that the determination of their thermal inertia is very sensitive to their spin vector, while the diameter is rather easy to be constrained to a certain range by combining multi-wavelength observational data. Thus, we set diameter and hence the geometric albedo as fixed parameters, and inferred the spin vector and thermal inertia of the targets. Further detailed analyses on these cometary bodies will shed light on our understanding of the detailed surfacial characteristics of them.

• Journal of the Korean Society of Food Science and Nutrition
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• v.29 no.2
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• pp.316-321
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• 2000

This study carried out to eluciate the cancer chemoprevention of Korean native fermented food, baechu kimchi using Comet assay (in other words, single cell microgel electrophoresis). For this purpose, baechu kimchi was fractionated by water, n-hexane, chloroform and ethyl acetate. 5 strains of dominant fermented bacteria were isolated from baechu kimchi. The water fraction, n-hexane fraction, chloroform fraction, ethyl acetate fraction and water insoluble fractions showed no antigenotoxicitie in non-tumoral normal 3T3 cells. Among 5 bacteria isolates from baechu kimchi, two isolates bacteria 1 and 2 strongly inhibited genotoxicity of N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) in non-tumoral normal 3T3 cells (p<0.05). Bacteria 3, 4 and 5 were also not antigenotoxic.

• Proceedings of the Korean Nuclear Society Conference
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• 1999.05a
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• pp.388-388
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• 1999

• Korean Journal of Ecology and Environment
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• v.41 no.4
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• pp.466-471
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• 2008

Little is known about DNA-level and physiological levels for health assessments of stream or river environments. Recently, comet assay, so called Single Cell Gel Electrophoresis (SCGE) is introduced for assessments of DNA damage in the medical science, food science and mammal toxicology. The comet assay is known as a biomarker which is one of the best barometers in assessing the DNA damage by oxidative stress. In this study, we conducted the comet assay using sentinel species, Zacco platypus, as one of the pre-warning alarm systems for the aquatic ecosystem health assessments and also applied it to Gap Stream as a model system. Tail extent moments in the S1 and S2 were 5.20 and 9.90 respectively and the moment was 19.89 in the S3. Statistical ANOVA in the tail moments showed a significant difference (n=75, p<0.05) between S1 and S3. Also, the proportions of DNA in the tail were 14.47, 23.64, and $30.04{\mu}m$ in the upstream (control site), midstream, downstream sites, respectively. Our results in the downstream were accord with previous studies of individual-level, population-level, and community-level in Gap Stream. Our results suggest that the comet assay may be used as an important tool for diagnosing ecological health of aquatic ecosystems in the level of DNA.

• Environmental Mutagens and Carcinogens
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• v.21 no.2
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• pp.89-94
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• 2001

Recently, single cell gel electrophoresis, also known as comet assay, is widely used for the detection and measurement of DNA strand breaks in vitro and in vivo in many toxicological fields such as radiation exposure, human monitoring and toxicity evaluation. As well defined, comet assay is a sensitive, rapid and visual method for the detection of DNA strand breaks in individual cells. Briefly, a small number of damaged cells suspended in a thin agarose gel on a microscope slide were lysed, unwinded, electrophoresed, and stained with a fluorescent DNA binding dye. The electric current pulled the charged DNA from the nucleus such that relaxed and broken DNA fragments migrated further. The resulting images which were subsequently named for their appearance as comets, were measured to determine the extent of DNA damages. However, some variations could be occurred in procedures, laboratories's conditions and kind of cells used. Hence, to overcome and to harmonize these matters in comet assay, International Workshop on Genotoxicity Test Procedure (IWGTP) was held with several topics including comet assay at Washington D.C. on March, 1999. In spite of some consensus in procedures and conditions in IWGTP, there are some problems still remained to be solved. In this respect, we attempted to set the practical optimal conditions in the experimental procedures such as lysis, unwinding, electrophoresis and neutralization conditions and so on. First of all, we determined optimal lysis and unwinding time by using 150 $\mu$M methyl methanesulfonate (MMS) which is usually used concentration. And then, we determined optimal positive control concentrations of benzo(a)pyrene (BaP) and MMS in the presence and absence of S9 metabolic activation system, respectively.

• Journal of Korean Biological Nursing Science
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• v.3 no.2
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• pp.21-33
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• 2001

The objective of this study was to examine the effects of antioxidant vitamins on the cellular oxidant damage by observing the mitogenicity in the mouse spleen and the strand breaks of DNA in mouse blood induced by $AFB_2$. Intraperitoneal(i.p.) injections of vitamin C(VC) of 10 mg/kg and vitamin E(VE) of 63.8 mg/kg were repeatedly administered to male ICR mice of 6 weeks old at intervals of 4 times every 2 days. After one hour vitamin treatments, $AFB_1$ of 0.4 mg/kg was injected into the $AFB_2$ plus vitamin treated groups in the same way. On the other hands, into the $AFB_2$ only treated group, only $AFB_2$ was injected without vitamins in the same method as above. The results of the experiment are as follows ; as regard to comet assay, DNA strand breaks were clearly present and they formatted a typical comet tail in the mice blood of the $AFB_2$ only treated groups. However, comet tails apparently disappeared in $AFB_2$ plus antioxidant vitamins treated groups since oxidant damage was controlled in an almost similar level to the control group. Mitogenicity of the spleen also showed a similar tendency as before, and these differences were more remarkably observed in the reaction against Con-A, which is a T-cell mitogen. In these data, the statistical significance was p<0.01. The LDL and VLDL levels were 408.72, 504.47 mg/dl respectively in the $AFB_2$ only treated groups. Compared with the $AFB_1$ only treated groups, those of $AFB_2$ plus antioxidant vitamin treated groups decreased to 272.06(VC), 305.28 mg/dl(VE), respectively. On the other hand, HDL levels were diminished to 32.60, 29.60 mg/dl in $AFB_2$ only treated groups, compared to 42.23, 41.14 mg/dl in the $AFB_2$ plus antioxidant vitamins treated groups. But, blood glucose levels were not statistically significant.