• Title, Summary, Keyword: Sample Preparation

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Technical Overview on the Electron Backscattered Diffraction Sample Preparation

  • Kim, Dong-Ik;Kim, Byung-Kyu;Kim, Ju-Heon
    • Applied Microscopy
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    • v.45 no.4
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    • pp.218-224
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    • 2015
  • A technical overview on the various sample preparation methods for electron backscattered diffraction (EBSD) analysis is carried out. The mechanical polishing with colloidal silica finish, electro-chemical polishing, dual layer coating and ion beam milling are introduced for the common sample preparation methods for EBSD observation and some issues that are frequently neglected by the common EBSD users but should be considered to get a reliable EBSD data are discussed. This overview would be especially helpful to the people who know what EBSD technique is but do not get a reliable EBSD data because of difficulties in sample preparation.

Transmission Electron Microscopy Specimen Preparation of Delicate Materials Using Tripod Polisher

  • Cha, Hyun-Woo;Kang, Min-Chul;Shin, Keesam;Yang, Cheol-Woong
    • Applied Microscopy
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    • v.46 no.2
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    • pp.110-115
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    • 2016
  • Transmission electron microscopy (TEM) is a powerful tool for analyzing a broad range of materials and provides localized information about the microstructure. However, the analysis results are strongly influenced by the quality of the thin foil specimen. Sample preparation for TEM analysis requires considerable skill, especially when the area of interest is small or the material of interest is difficult to thin because of its high hardness and its mechanical instability when thinned. This article selectively reviews recent advances in TEM sample preparation techniques using a tripod polisher. In particular, it introduces two typical types (fl at type and wedge type) of TEM sample preparation and the benefits and drawbacks of each method; finally, a method of making better samples for TEM analysis is suggested.

Discussions about Sample Preparation Techniques for Oxygen and Hydrogen Isotope Analysis (산소와 수소 동위원소 분석을 위한 시료 전처리 기술에 대한 고찰)

  • Lee, Kwang-Sik;Lee, Insung
    • Economic and Environmental Geology
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    • v.29 no.2
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    • pp.207-214
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    • 1996
  • For many years oxygen and hydrogen isotope analysis have been used as one of the most valuable research tools to investigate many geological processes. There are many sample preparation techniques of oxygen and hydrogen isotope analysis for various geological samples. We introduce here several important sample preparation techniques for oxygen and hydrogen isotope analysis and discuss the problems of each method in detail.

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Sample Preparation of Ductile Heterogeneity Materials by Ultramicrotomy (연성 이종 재료 시료의 상온 절편 제작법)

  • Chae, Hee-Su;Kweon, Hee-Seok;Je, A-Reum;Lee, Seok-Hoon;Kim, Jin-Gyu
    • Applied Microscopy
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    • v.42 no.1
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    • pp.49-52
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    • 2012
  • For TEM study of biological samples or polymers that are contained in organic structure, it is often required that the sample is prepared by using ultramicrotome and stained with proper agents to increase the contrast of organic structure. In this study, we investigated an efficient TEM sample preparation method for ductile heterogeneity material by using ultramicrotomy. Cryo-ultramicrotomy is a suitable method that is capable of rendering sample hardness for various ductile materials. However, it has several factors to consider, such as experimental cost, working time and finding the optimal staining conditions. To satisfy these considerations, we prepared TEM sample by using ultramicrotome without cryofunction, and secured the sample hardness by applying the staining process prior to ultrathin sectioning. The cross-linked polyethylene structure in the sample was stained with the 2% $RuO_4$ solution in a sealed test tube for 24 hours at $4^{\circ}C$. After the sample staining, ultrathin sections of sample were prepared using ultramicrotome. As a result, it was revealed that the difficulties associated with staining of ultrathin sections prepared by low-temperature conditions were improved. In addition, appropriate staining depth of sample could be selected for sectioning process. The quality of TEM sample obtained by using this method was better than that of cryo-ultramicroscopy. Finally, it is expected that our method could be effectively applied in TEM sample preparation for a variety of nano-bio convergence materials.

Sample Preparation for Matrix-Assisted Laser Desorption/Ionization Mass Spectrometry

  • Kim, Jeongkwon
    • Mass Spectrometry Letters
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    • v.6 no.2
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    • pp.27-30
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    • 2015
  • This article reviews the fundamentals of sample preparation used in matrix-assisted laser desorption/ionization-mass spectrometry (MALDI-MS). MALDI is a soft ionization method used to generate analyte ions in their intact forms, which are then detected in MS analysis. MALDI-MS boasts fast analysis times and easy-to-use operation. The disadvantages of MALDI-MS include the occurrence of matrix-associated peaks and inhomogeneous distribution of analyte within the matrix. To overcome the disadvantages of MALDI-MS, various efforts have been directed such as using different matrices, novel matrix systems, various additives, and different sample preparation methods. These various efforts will be discussed in detail. This article will benefit those who would like to obtain basic knowledge of MALDI sample preparation and those who would like to use MALDI-MS in their chemical analyses.

Transmission Electron Microscopy Sample Preparation of Ge2Sb2Te5 Nanowire Using Electron Beam

  • Lee, Hee-Sun;Lee, Jun-Young;Yeo, Jong-Souk
    • Applied Microscopy
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    • v.45 no.4
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    • pp.199-202
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    • 2015
  • A simple and novel transmission electron microscopy (TEM) sample preparation method for phase change nanowire is investigated. A $Ge_2Sb_2Te_5$ (GST) nanowire TEM sample was meticulously prepared using nanomanipulator and gas injection system in a field emission scanning electron microscopy for efficient and accurate TEM analysis. The process can minimize the damage during the TEM sample preparation of the nanowires, thus enabling the crystallographic analysis of as-grown GST nanowires without unexpected phase transition caused by e-beam heating.

Sample Preparation and Nucleic Acid-based Technologies for the Detection of Foodborne Pathogens (식중독균의 검출을 위한 시료전처리 및 핵산기반의 분석기술)

  • Lim, Min-Cheol;Kim, Young-Rok
    • Food Engineering Progress
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    • v.21 no.3
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    • pp.191-200
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    • 2017
  • There have been great efforts to develop a rapid and sensitive detection method to monitor the presence of pathogenic bacteria in food. While a number of methods have been reported for bacterial detection with a detection limit to a single digit, most of them are suitable only for the bacteria in pure culture or buffered solution. On the other hand, foods are composed of highly complicated matrices containing carbohydrate, fat, protein, fibers, and many other components whose composition varies from one food to the other. Furthermore, many components in food interfere with the downstream detection process, which significantly affect the sensitivity and selectivity of the detection. Therefore, isolating and concentrating the target pathogenic bacteria from food matrices are of importance to enhance the detection power of the system. The present review provides an introduction to the representative sample preparation strategies to isolate target pathogenic bacteria from food sample. We further describe the nucleic acid-based detection methods, such as PCR, real-time PCR, NASBA, RCA, LCR, and LAMP. Nucleic acid-based methods are by far the most sensitive and effective for the detection of a low number of target pathogens whose performance is greatly improved by combining with the sample preparation methods.

Fabrication and Application of Micro Polymer Chip Platform for Rare Cell Sample Preparation (희귀 세포 샘플 준비를 위한 마이크로 폴리머 칩 플랫폼 제작 및 활용)

  • Park, Taehyun
    • Journal of the Korea Convergence Society
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    • v.9 no.3
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    • pp.217-222
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    • 2018
  • In this paper, a new micro polymer chip platform and protocol were developed for rare cell sample preparation. The proposed platform and protocol overcome the current limitation of the dilution method which is based on statistics and the FACS method which expensive and requires fluorescence staining. It allows collecting exact number of target cells simply and selectively because the cells are visually confirmed during the collecting process. The collected cells can be transported or spiked into a desired locations, such as a microchamber, without cell loss. This research may applicable not only to a rare cell sample preparation for Lab on a Chip cancer diagnosis, but also to a single/double/multiple cell sample preparation for a cell analysis field. To verify this platform and protocol, five human breast cancer cells (MCF-7) were collected and transported into a hemocytometer chamber.

Optimization of One-step Extraction/Methylation Method for Analysis of Fatty Acid Composition in Brown Rice

  • Cho, Kyoung-Shim;Kim, Hyun-Ju;Moon, Sang-Mi;Kang, Jung-Hoon;Lee, Young-Sang
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.51 no.1
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    • pp.89-94
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    • 2006
  • Traditionally fatty acid composition used to be analysed by a GC and the sample preparation process includes lipid extraction from sample and subsequent methyl esters preparation, which are time-consuming and cumbersome. As an alternative, simultaneous extraction/methylation methods are being developed for rapid and simplified sample preparation. To optimize one-step extraction/methylation method for analysis of fatty acid composition in brown rice, various reaction factors such as sample to reaction solution ratio, reaction time and temperature, shaking intensity were changed and resultant fatty acid composition data were evaluated in comparison with previous reports. The ratio of sample weight to reaction solution volume was the most critical factor in that higher sample to reaction solution ratio caused overestimation of palmitic acid and linoleic acid composition, resulting in underestimation of oleic acid. Lower reaction temperature also induced overestimation of linoleic acid and underestimation of oleic acid. Reaction duration and the intensity of shaking prior to and during the reaction, however, caused no significant changes in analysis results. In conclusion, the optimum condition was mixing 5 grains (about 0.2 g) of brown rice with $680{\mu}L$ of extraction/methylation mixture and $400{\mu}L$ of heptane, followed by reaction at $80^{\circ}C$ for 2 hours.