• 한국세라믹학회지
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• 제45권10호
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• pp.605-609
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• 2008

This work describes the preparation of functionalized magnetic nanoparticles(MNPs) and their bioapplication to human DNA separation. Silica coated MNPs were prepared by changing the volume ratio of tetraethyl orthosilicate(TEOS) for controlled coating thickness on the original nanoparticle of MNPs. The sol-gel process in silica coating on MNPs surface was adapted for relatively mild reaction condition, low-cost, and surfactant-free. And then amino functionalized magnetic nanoparticles were synthesized using amine groups as surface modifiers. The result of adsorption efficiency for human DNA with amino-functionalized silica coated MNPs was calculated as a function of the number of amine groups.

• Bulletin of the Korean Chemical Society
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• 제24권7호
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• pp.943-947
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• 2003

We have studied the migration behavior of single-stranded DNA using capillary gel electrophoresis under various conditions. It was found that optimum electric fields should be less than 150 V/cm for the good tradeoff between the separation time and the resolution. It seems that the gel matrix with the combination of different polymer average molecular weights is important to extend the maximum readable DNA bases. The total gel concentration less than 3.1% in the mixed gel system showed good separation efficiency up to 600 bases. The best result was obtained with the poy(ethylene)oxide (PEO) gel concentration of 1.2% of Mr 8,000,000 and 1.8% of Mr 600,000. We observed that the capillary length between 50 cm to 100 cm (effective length) should be employed for the optimization between the total DNA migration time and the maximum readable length. A trizma base-boric acid-ethlyenediaminetetraacetic acid (EDTA) (TBE) buffer was commonly used for DNA sequencing, but we found that 3-[tris(hydroxymethyl)methyl amino]-1-propane sulfonic acid (TAPS) buffer worked as well for the single-stranded DNA separation. Especially, TAPS buffer showed a good resolution for very short DNA bases (1 to 30 bases).

• 대한기계학회논문집A
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• 제28권8호
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• pp.1135-1139
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• 2004

This paper presents a microextractor for the separation of DNA molecules by their sizes. The DNA microextractor immobilizes the DNA molecules of specific size in the micropillar array by adjusting the period of the crossed electric field, thus providing a starting-point independent target DNA extraction method without separation process monitoring. The DNA microextractor has been fabricated by a three-mask micromachining process. The velocity of three different DNA molecules has been measured at the electric field of E=5V/0.8cm in the fabricated DNA microextractor, resulting in the reorientation times of $4.80{\pm}0.44sec,\;7.12{\pm}0.75sec$, and $9.88{\pm}0.30sec$ for ${\lambda}$ DNA, micrococcus DNA, and T4 DNA, respectively. T4 DNA is trapped in the micropillar array when the crossed electric field of 5V/0.8cm is applied alternately at a 10 second time interval. The present DNA microextractor filters the DNA in a specific size range by adjusting the magnitude and/or the period of the crossed electric field applied in the micropillar array.

• Bulletin of the Korean Chemical Society
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• 제27권4호
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• pp.519-523
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• 2006

Poly(dimethyl siloxane) (PDMS) has been employed as a microchip material for DNA separation in microfluidic condition. Different sieving molecules such as cellulose derivatives having glucose building block (methyl cellulose (MC), hydroxyethyl cellulose (HEC), and hydroxypropyl methyl cellulose (HPMC)) and polyethylene oxide (PEO) having linear (ring-opened ethylene oxide) unit were used and their performance was compared in terms of separation efficiency and resolution. In general, PEO showed better separation performance than cellulose derivatives probably due to the nature of linear shape polymer conformation. It was possible to perform at least 15 consecutive running with 1.2% PEO at the electric field strength around 200 V/cm. Fast analysis of the standard $\Phi$X 174 RF DNA/Hae III (less than 130s) was obtained with the number of the theoretical plate around 250,000/m. Our PMDS microchip was applied to the measurement of CAG repeat number, which is related to male infertile disease.

• 미생물학회지
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• 제39권2호
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• pp.114-117
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• 2003

유전자의 기능을 분석하는 과정에서 특정한 염기 서열의 존재여부를 확인하는 분석법은 필수적이다. 현재 사용되고 있는 Southern및 Northern blotting방법은 시간이 오래 걸리며, 온도 등과 같은 외부 조건을 엄격하게 조절하여야 한다. 본 연구에서는 측방유동방식을 이용한 크로마토그라피법을 응용하여 새로운 간편용 DNA분석법을 개발하였다. 이 측방유동형 DNA 분석 스트립은 시료가 적용되는 샘플패드, 이동하여 분리되고 교잡반응이 일어나는 전개용 막, 그리고 시료가 계속하여 이동하기 위한 흡수패드로 구성되어 있다. 모델 시스템으로 HIV와 HCV에 대한 포획 및 표적 DNA를 합성하고 스트립을 제조하였다. 시료를 샘플패드에 적하한 후 교잡반응체의 생성여부와 상대적인 양은 GSI형광 스캐너로 분석하였다. 교잡반응이 매우 빠르게 진행되고 세척과정이 없음에도 불구하고 비특이적인 교차 반응이 거의 관찰되지 않았다. 기존의 DNA 교잡방법과 비교하여 볼 때 이 새로운 방법으로 DNA/DNA 교잡 실험을 보다 더 쉽고, 간편하고, 그리고 빠르게 할 수가 있을 것으로 예상된다.

• Bulletin of the Korean Chemical Society
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• 제32권7호
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• pp.2217-2221
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• 2011

We investigated the selective deoxyribonucleic acid (DNA) adsorption on layered double hydroxide (LDH) nanoparticles via studying the interaction between positively charged LDH nanoparticle as adsorbent and negatively charged adsorbates such as methyl orange (MO), fluorescein (FL), and DNA strands. The size controlled LDH $(Mg_{0.78}Al_{0.22}(OH)_2(CO_3)_{0.11}{\cdot}mH_2O)$ was prepared by conventional coprecipitation method, followed by the hydrothermal treatment. According to the adsorption isotherms, the adsorbed amounts of MO and FL were similar, however, that of DNA were much larger. The adsorption behaviors were well fitted to Freundlich adsorption model. The concentration dependent adsorption behavior on LDH surface was described in order to verify the selective DNA separation ability. The result showed that the LDH has advantages in selective adsorption of DNA competing with single molecular anions.

• Korean Chemical Engineering Research
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• 제48권1호
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• pp.88-92
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• 2010

DNA 구조를 밝히기 위해 의학, 약학 그리고 생명과학분야 등에서 활발한연구가 이루어지고 있다. 그 중 DNA의 염기쌍은 생명체의 정보 전달에 매우 중요한 역할을 하므로 염기쌍의 집중적인 분석이 필요하다. 그래서 DNA의 염기쌍 중 하나인 구아닌과 시토신을 선택하여 분석 실험을 하였다. 구아닌과 시토신의 분석은 Aspen chromatography 전산모사와 HPLC(High Performance Liquid Chromatography) 실험을 통하여 이루어졌다. Aspen Chromatography(ver. 2006 Aspen Tech. U.S.A)로 시료농도, 이동상 유속 그리고 이론단수를 변화시켜 전산모사하였다. HPLC 실험은 $C_{18}$ HPLC column 칼럼과 이동상 water/methanol/acetic acid 혼합액(90/10/0.1)을 이용하여 시료의 주입 농도와 이동상 속도를 변화시켰고 구아닌과 시토신의 크로마토그램의 분리도와 이론단수를 비교하였다. 실험과 전산모사 크로마토그래피 결과가 비교적 일치하였다.

• Biotechnology and Bioprocess Engineering:BBE
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• 제5권3호
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• pp.191-195
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• 2000

Quantitation of N7-methyldeoxyguanosine (N7-MedG) produced in the in vitro N-methly-N-nitrosuourea (NMU) action on thymus DNA has been achieved by enzymatic degradation, liquid chromatoraphic separaphic separation and desorption chemical ionization tandem mass spectrometry. In conjunction with the resolving power HPLC in the separation of isomers, desorprion chemical ionization tandem mass spectrometry has utilized in determining modified nucleosides at low levels using a stable-isotope labled compound as an internal reforence. The quantitative estimation of N7-methyldeoxyguanosine was previously established by an independent HPLC analysis of methylated calf thymus DNA. A sensitive and specific methodogy for the quantitation of N7-MedG at the picomole level using HPLC combined with tandem mass spectrometry without radioisotope labeling process is presented. The potential of the liquid chromatoraphic tandem mass exposure to methlation agents in vitro.

• Journal of Microbiology
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• 제40권4호
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• pp.319-326
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• 2002

Cellular DNA in prokaryotes is organized in nucleic acid-protein self-assemblies referred to as the nucleoid. The physical forces responsible for its stability inside the poor solvent properties of the cytoplasm and their functional implications are not understood. Studies on the organisation and functioning of the cytosol of cells largely rely on experimental protocols performed in highly dilute solutions using biochemically purified molecules, which is not a reliable substitute for the situation existing in vivo. Our current research interest is focused on the characterization of biological and physical forces determining the compaction and phase separation of DNA in Escherichia coli cytoplasm. We have emphasized the effect of excluded volume in solutions with high macromolecular concentrations (macromolecular crowding) upon self-association patterns of reactions. The prokaryotic cytosol was simulated by addition of inert polymer polyethylene glycol (PEG) (average molecular weight 20000), as an agent which afterwards facilitates the self-association of macromolecules. Fluorescence microscopy was used for direct visualization of nucleoids in intact cells, after staining with DAPI (4',6-diamidino-2-phenylindole dihydrochloride). Addition of the crowding agent PEG 20,000, in increasing concentrations generated progressively enhanced nucleoid compaction, the effect being stronger in the presence of 0.2 M NaCl and 5 mM MgCl$\_$2/. Under these conditions, the nucleoids were compacted to volumes of around 2 ㎛$\^$3/ or comparable sizes with that of living cells.

• Animal Systematics, Evolution and Diversity
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• 제36권3호
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• pp.268-273
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• 2020

A spionid polychaete, Boccardiella hamata (Webster, 1879) has been found from mud in crevices between the shells of oysters and adherent substrates in South Korea. The sequences of mitochondrial DNA (mtDNA) cytochrome c oxidase subunit 1 (CO1), 16S ribosomal DNA (16S), and the nuclear 18S ribosomal DNA (18S) from Korean individuals of Boccardiella hamata were determined in the present study. The molecular analysis based on the 18S rRNA gene sequences showed clear separation among the spionid polychaete species, and the sequences of Korean and Japanese individuals are completely identical. The morphological diagnosis and photographs of B. hamata are also provided.