• 산업식품공학
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• 제21권3호
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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.

• 한국융합학회논문지
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• 제9권3호
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• pp.217-222
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• 2018

본 논문에서는 정확한 수의 희귀 세포 포집 및 이송을 위한 마이크로 폴리머 칩 플랫폼의 디자인과 제작, 그리고 프로토콜을 소개하고 있다. 본 플랫폼과 프로토콜은 기존의 통계학적인 샘플 준비 방법인 희석(Dilution)의 한계와 고가이며 형광염색이 요구되는 유세포분석기(Fluorescence activated cell sorter)의 단점을 극복하였다. 타켓 세포를 선택적으로 쉽고 간단하게 채집할 수 있으며 채집되는 세포의 수는 시각적으로 검증되므로 매우 정확한 방법이다. 또한, 채집된 세포들은 마이크로 챔버 등의 원하는 곳으로 세포의 손실 없이 이송 또는 주입 시킬 수 있다. 본 연구는 암진단 등을 목적으로 하는 칩 속의 실험실(Lab on a chip) 등에 필요한 희귀 세포 샘플 준비를 위해 활용 될 수 있을 뿐만 아니라 세포분석을 위한 싱글/더블/다수 세포 샘플의 준비에도 활용 가능하다. 본 논문에서 제시하는 세포 채집 플랫폼과 프로토콜을 검증하기 위해 5개의 인간 암세포(MCF-7)를 채집한 뒤 세포계수기(Hemocytometer) 안으로 주입시켜 세포의 수를 확인하였다.

• 한국연초학회지
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• 제22권1호
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• pp.91-98
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• 2000

This study was carried out to evaluate the uncertainty in the analysis of menthol content from the mentholated cigarette. Menthol in the sample cigarette was extracted with methanol containing an anethole as an internal standard, and then analyzed by gas chromatography. As the sources of uncertainty associated with the analysis of menthol, were the following points tested, such as the weighing of sample, the preparation of extracting solution, the pipetting of extracting solution into the sample, the preparation of standard solution, the precision of GC injections for standard & sample solution, the GC response factor of standard solution, the reproducibility of menthol analysis, and the determination of water content in tobacco, etc. For calculating the uncertainties, type A of uncertainty was evaluated by the statistical analysis of a series of observation, and type B by the information based on supplier's catalogue and/or certificated of calibration. Sources of uncertainty were subsequently included and mathematically combined with the uncertainty arising from the assessment of accuracy to provide the overall uncertainty. It was shown that the main source of uncertainty came from the errors in the reproducibility of menthol and water determination, the purity of menthol reference material in the preparation of standard solution, and the precision of GC injections for sample solution. The errors in sample weighing and volume measurement contributed relatively little to the overall uncertainty. The expanded uncertainty in the mentholated cigarettes, Korean and American brand, at 0.95 level of statistical confidence was $\pm$0.06 and $\pm$0.07 mg/g for a menthol content of 1.89 and 2.32 mg/g, respectively.

• Applied Microscopy
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• 제45권4호
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• pp.203-207
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• 2015

Sample preparation is very important for crystal structure analysis of novel nanostructured materials in electron microscopy. Generally, a grid dispersion method has been used as transmission electron microscope (TEM) sampling method of nano-powder samples. However, it is difficult to obtain the cross-sectional information for the tabular-structured materials. In order to solve this problem, we have attempted a new sample preparation method using focused ion beam. Base on this approach, it was possible to successfully obtain the electron diffraction patterns and high-resolution TEM images of the cross-section of tabular structure. Finally, we were able to obtain three-dimensional crystallographic information of novel zeolite nano-crystal of the tabular morphology by applying the new sample preparation technique.

• 한국세라믹학회지
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• 제55권4호
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• pp.376-380
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• 2018

Microstructural characterization of Ni-yttria-stabilized zirconia (YSZ) anodes using secondary electron images has been limited by a lack of contrast between Ni and YSZ phases. This paper reports a sample preparation method for obtaining secondary electron images that allow the detection of Ni, YSZ, and pore phases together. Ni-YSZ anode samples were obtained by reducing NiO-YSZ samples prepared by using the mixed oxide method. Colloidal silica polishing and electrolytic etching were performed on the Ni-YSZ samples. The morphological change of the sample surface after each polishing process is examined.

• 한국어병학회지
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• 제34권2호
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• pp.261-269
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• 2021

This study presents the evaluation of sample extraction and purification procedure for the determination of residues of febantel and its metabolites, fenbendazole, oxfendazole and oxfendazole sulfone in rockfish (Sebastes schlegeli) muscle using liquid chromatography-tandem mass spectrometry. Residues of febantel and its metabolites in rockfish muscle were analyzed using each different sample preparation method from Korean Food Standards Codex (KFSC), Food Safety and Inspection Service (FSIS, USA), and the modified FSIS method using QuEChERS kit (FSIS-Q), respectively. Each method was compared for mean recoveries and repeatabilities. Since FSIS-Q showed higher repeatabilities (coefficient of variation, CV of 2.4%~10.9%) than those of FSIS method (CV of 4.6%~17.5%), recoveries from FSIS-Q were compared with those from KFSC method. FSIS-Q showed significantly higher recoveries of 83.1%~110.1% (P < 0.05) than those from KFSC method of 64.7%~107.4%. In addition, FSIS-Q showed a good linearity over the range of 2.5~200 ㎍/kg, and excellent sensitivities with limit of detection of 0.46~0.71 ㎍/kg and limit of quantification of 1.08~2.15 ㎍/kg. Although all the sample preparation methods turned out to be able to meet CODEX guideline for all the compounds, FSIS method and FSIS-Q validated in this study could be applied to screening and quantification for residues of febantel and its metabolites in rockfish muscle with efficient preparation procedures.

• 한국근적외분광분석학회:학술대회논문집
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• 한국근적외분광분석학회 2001년도 NIR-2001
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• pp.1022-1022
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• 2001

To obtain accurate and repeatable analyses using NIR technology it is important to select an NIR instrument and / or its sample presentation attachments which allow the operator to minimize sampling errors without compromising the benefits of NIR analysis -namely rapid, low cost, minimal sample preparation, minimal structural facilities, minimal hazards. For each sample type and consistency there may be different optimal combinations of instrument, sample presentation attachment, and sample preparation. This paper will consider options available to NIR users in the area of plant and soil analysis and evaluate the potential benefits and disadvantages of crop nutrient diagnoses using laboratory based and airborne imaging techniques.

• 대한기계학회논문집A
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• 제34권12호
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• pp.1785-1791
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• 2010

중합효소 연쇄반응(PCR)을 수행하려면 세포 용해(cell lysis)와 DNA추출(DNA purification)과정이 포함된 시료 전처리 과정을 거쳐야 한다. 종래의 시료 전처리 과정은 계면활성제와 같은 세포용해 버퍼를 이용하거나 열 또는 전기적 방법으로 세포막 파열을 유도하여 세포벽을 깬 후에 잔여물 처리과정을 거쳐 DNA를 추출하게 된다. 본 연구에서는 마이크로 비드와 PDMS 기둥을 이용한 필터가 있는 시료 전처리용 바이오칩을 설계 및 제작하였다. 또한 제작된 바이오칩을 사용하여 $80^{\circ}C$에서 2분간 세포용해를 수행하고 DNA를 추출하였다. 칩에서 전처리과정을 거친 시료내의 DNA농도와 순도를 측정하고 DNA PCR과 겔 전기영동을 통해 시료 전처리용 바이오칩의 성능을 평가하였다.

• JSTS:Journal of Semiconductor Technology and Science
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• 제1권4호
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• pp.232-238
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• 2001

A new DNA purification chip is proposed and fabricated for the sample preparation of Nucleic Acid (NA) probe assay. The proposed DNA purification chip is fabricated using photosensitive glass substrate and polydimethylsiloxane (PDMS) cover fixture. We have successfully captured and eluted the DNA using the fabricated photosensitive glass chip. The fabricated DNA purification chip showed a binding capacity of $15ng/\textrm{cm}^2$and a minimum extractable input concentration of $100copies/200\muL$. The proposed DNA purification chip can be applied for low-cost, disposable sample preparation of NA probe assays.

• 펄프종이기술
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• 제48권1호
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• pp.5-18
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• 2016

Electron microscopy is an important investigation and analytical method for the morphological characterization of various cellulosic materials, such as micro-crystalline cellulose (MCC), microfibrillated cellulose (MFC), nanofibrillated cellulose (NFC), and cellulose nanocrystals (CNC). However, more accurate morphological analysis requires high-quality micrographs acquired from the proper use of an electron microscope and associated sample preparation methods. Understanding the interaction of electron and matter as well as the importance of sample preparation methods, including drying and staining methods, enables the production of high quality images with adequate information on the nanocellulosic materials. This paper provides a brief overview of the micro and nano structural analysis of cellulose, as investigated using transmission and scanning electron microscopy.