• Title/Summary/Keyword: Strand method

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Determination of Repeat Numbers of (CA)n in Mitochondrial D-loop using Polymerase Chain Reaction-single Strand Conformational Polymorphism (PCR-SSCP) (중합효소연쇄반응-단일가닥입체형태다형태 방법을 이용한 미토콘드리아 D-고리에서의 CA 디뉴클레오티드 반복수의 결정)

  • Kim, Joo-Young;Kim, Dae-Kwang
    • Anatomy & Biological Anthropology
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    • v.31 no.3
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    • pp.77-82
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    • 2018
  • Polymerase chain reaction-single strand conformational polymorphism (PCR-SSCP) analysis is a kind of sensitive mutation detection method that has been usually used in field of medical genetics. A single DNA strand with a mutation or nucleotide polymorphism has a different conformation from its wild-type counterpart, and these conformational differences result in different electrophoretic mobility. In previous study of mitochondrial microsatellite instability in 50 uterine leiomyomas, PCR-SSCP showed 4 types of band mobility at (CA)n of the mitochondrial D-loop. In type 1 and 4, positions of the lower single stand of both were same but those of upper strand were different. In sequencing analysis, repeat number of (CA)n in type 1 was 4, 5 in type 2, 6 in type 3, and 4 in type 4, respectively. Without using expensive sequencing analysis, PCR-SSCP method can be used to detect the repeat number of(CA)n in mitochondrial D-loop.

DNA Single Strand Breaks of Perchloroethylene and Its Bio-degradation Products by Single Cell Gel Electrophoresis Assay in Mammalian Cell System

  • Jeon, Hee-Kyoung;Kim, Young-Seok;Sarma, Sailendra Nlath;Kim, Youn-Jung;Sang, Byoung-In;Ryu, Jae-Chun
    • Molecular & Cellular Toxicology
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    • v.1 no.2
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    • pp.99-105
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    • 2005
  • Perchloroethylene (tetrachloroethylene, PCE), a dry cleaning and degreasing solvent, can enter ground-water through accidental leak or spills. PCE can be degraded to trichloroethylene (TCE), 1, 1-dichloroethylene (DCE) and vinyl chloride (VC) as potential bio-product. These compounds have been reported that they can cause clinical diseases and cytotoxicity. However, only a little genotoxic information of these compounds has been known. In this study, we investigated DNA single strand breaks of PCE, TCE, DCE and VC by single cell gel electrophoresis assay, (comet assay) which is a sensitive, reliable and rapid method for DNA single strand breaks with mouse lymphoma L5178Y cells. From these results, $37.5\;{\mu}g/ml$ of PCE, $189\;{\mu}g/ml$ of TCE and $56.4\;{\mu}g/ml$ of DCE were revealed significant DNA damages in the absence of S-9 metabolic activation system meaning direct-acting mutagen. And in the presence of S-9 metabolic activation system, $41.5\;{\mu}g/ml$ of PCE, $328.7\;{\mu}g/ml$ of TCE and $949\;{\mu}g/ml$ of DCE were induced significant DNA damage. In the case of VC, it was revealed a significant DNA damage in the presence of S-9 metabolic activation system. Therefore, we suggest that chloroethylene compounds (PCE, TCE, DCE and VC) may be induced the DNA damage in a mammalian cell.

Optimal Conditions of Single Cell Gel Electrophoresis (Comet) Assay to detect DNA single strand breaks in Mouse Lymphoma L5178Y cells

  • Ryu, Jae-Chun;Kwon, Oh-Seung;Kim, Hyung-Tae
    • 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.

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A Study on the Combustion Characteristics of Composite Solid Propellants at Low Pressure using Vacuum Strand Burner (Vacuum Strand Burner를 이용한 혼합형 고체 추진제의 저압 연소특성 연구)

  • 박영규;유지창;김인철;이태호
    • Journal of the Korean Society of Propulsion Engineers
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    • v.3 no.1
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    • pp.95-103
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    • 1999
  • Low pressure combustion characteristics of the composite solid propellants were studied in terms of the propellant burning rate, ignition processes, and the structure of the extinguished surfaces. Optical Vacuum Strand Burner(OVSB) system was designed and configured for this purpose. Burning rates of the propellants were measured at subatmospheric pressure by developed test method in OVSB. The ignition and combustion phenomena of the studied propellants in the combustion chamber of OVSB were recorded and analyzed with the camera and VCR(30 frames/s). Burning surfaces of the propellants were extinguished by rapid depressurization method and analyzed with Scanning Electron Microscope(SEM).

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XPS STUDY ON DNA DAMAGE BY LOW-ENERGY ELECTRON IRRADIATION

  • Noh, Hyung-Ah;Cho, Hyuck
    • Journal of Radiation Protection and Research
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    • v.36 no.4
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    • pp.190-194
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    • 2011
  • After the first report that electrons with sub-ionization energy of DNA could cause single strand breaks or double strand breaks to DNA, there have been various studies to investigate the mechanisms of DNA damage by low-energy electrons. In this paper, we examined the possibility of using X-ray photoelectron spectroscopy (XPS) to analyze the dissociation patterns of the molecular bonds by electron irradiation on DNA thin films and tried to establish the method as a general tool for studying the radiation damage of biomolecules by low energ yelectrons. For the experiment, pBR322 plasmid DNA solution was formed into the films on tantalum plates by lyophilization and was irradiated by 5-eV electrons. Un-irradiated and irradiated DNA films were compared and analyzed using the XPS technique.

Parametric Study for Conductor Design of KSTAR PF Coils

  • Yoon, Cheon-Seog;Qiuliang Wang;Kim, Myungkyu;Kim, Keeman;Lee, Dong-Ryul
    • Journal of Mechanical Science and Technology
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    • v.16 no.2
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    • pp.227-234
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    • 2002
  • Large superconducting magnets such as ITER (International Thermonuclear Experimental Research) or KSTAR (Korean Superconducting Tokamak Advanced Research) magnet system adopted a cable-in-conduit conductor (CICC) using a forced-flow cooling system. Main optimization criteria for the conductor design of superconducting magnet system are stability margin and CICC cooling requirements. A zero-dimensional method is applied for the calculation of stability and the conductor optimization. In order to increase conductor performance, three different strands, ITER HP-I and HP-II, and KSTAR HP-Ⅲ, are tested. The strand characteristics of KSTAR HP-Ⅲ are measured in the Samsung's PPMS and Jc measurement system, and applied for this study. Also, the strand diameters, 0.81 mm and 0.78 mm are considered for this study, due to design change. Based on this result, the proposed configuration of CICC has been fabricated.

A Study of Development for EMAT sensor of an Lorentz force type (Lorentz force 형태의 EMAT센서 개발에 관한 연구)

  • 정영재
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.7 no.2
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    • pp.9-14
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    • 1998
  • One of the areas in the continuous casting process that up to this point, has not been definitively instrumented is a method of reliably locating the part of a continuously cast strand that remains liquid for a period after the outer portion has solidified. To solve the problem. Electromagnetic Trandsducers(EMAT) which operate across an air gap without the need for a coupling medium has been developed. The system was designed to employ a through transmission technique which enhanced the signal-to-noise ratio. The Al 75$\times$75mm and 75$\times$100mm simulators with 2, 4, 8, 16, 32 mm hole respectively has been produced in order to verify the developed EMAT system and to measure to liquid core in continuous casting strand. The system developed can be employed for the optimization of torch cutting speed and for the final cut length of the bloom as well as calculation of average bloom temperature.

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Static and Dynamic Horizontal Earth Pressures against Vertical or Inclined Rigid Walls (연직 또는 경사진 강성벽체에 작용하는 정적 및 동적수평토압)

  • 김홍택
    • Geotechnical Engineering
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    • v.6 no.2
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    • pp.35-46
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    • 1990
  • An analytical solution method is described to estimate the developed static and dynamic horizontal earth pressures behind a vertical or inclined rigid wall experiencing outward toranslational movement. The results predicted by the developed method of analysis are compared with chose from the experimental model testg on sandy. The comparisons show good agreements at various stases of wall movement. When the wall i9 inclined with a certain angle in the direction of the supported strand sass, the effects of reduction in developed static and dynamic horizontal earth pressures are also analyzed. Finally, results of analytical parametric study are presented to demonstrate the effects of various parameters, such as wall friction angle and internal strand friction angle.

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The Measurement Technique of Burning Rate in Solid Proplellant at High Pressure (고체추진제의 고압 연소속도 측정기법)

  • Yoo, Ji-Chqang;Jung, Jung-Young;Yim, Yoo-Jin;Ko, Seung-Won
    • Journal of the Korean Society of Propulsion Engineers
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    • v.12 no.4
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    • pp.1-6
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    • 2008
  • The burning characteristics of HTPB/AP solid propellants were measured by closed bomb of internal volume of 200 cc and 700 cc up to 30,000 psia. The burning rates of closed bomb method showed good agreement with those of strand burner method between 1,000 psia and 5,000 psia, and the sharp increment of pressure exponent(n) around 6,000 psia as a result of testing in accordance with loading densities. The burning rate measured in 200 cc and 700 cc of internal volume of closed bomb agreed well without the relation of internal volume size.