• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.6
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• pp.1407-1413
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• 2009

The present study was conducted to gain insights into oocyte maturation and early embryo development, SELDI-TOF-MS was used to find the protein candidates that are specifically or prominently expressed in mouse oocytes at the in vitro matured metaphase II (MIl) and germinal vesicle (GV) stages. By using selected CM10 chip, found 16 candidates which were up-regulated in GV stage oocytes compared with in MIl stage oocytes, molecular weight are 8180 (2 candidates), 10226 (5 candidates), 15767 (5 candidates) and 16770 (4 candidates) Da respectively. And 29 candidates were higher in MIl than in GV stage oocytes, molecular weight are 10832 (3 candidates), 17744(8 candidates), 20122 (3 candidates), 22131 (3 candidates), 24857 (7 candidates) and 33507 (5 candidates) Da, respectively. All (45) candidate (0.2 and 1.0 % error tolerances) were performed real time RT-PCR analysis and further selected 13 more potential candidates.

• Journal of Sensor Science and Technology
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• v.27 no.4
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• pp.237-241
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• 2018

The real-time enrichment and detection of pathogens are serious issues and rapidly evolving field of research because of the ability of these pathogens to cause infectious diseases. In general, bacterial detection is accomplished by conventional colony counting or by polymerase chain reaction (PCR) after DNA extraction. As colony counting requires considerable time to cultivate, PCR is an attractive method for rapid detection. A small number of pathogens can cause diseases. Hence, a pretreatment process, such as enrichment is essential for detecting bacteria in an actual environment. Thus, in this study, we developed a microfluidic chip capable of performing rapid enrichment of bacteria and the extraction of their genes. A lectin, i.e., Concanavalin A (ConA), which shows binding affinity to the surface of most bacteria, was coated on the surface of magnetic particles to nonspecifically capture bacteria. It was subsequently concentrated through magnetic forces in a microfluidic channel. To lyse the captured bacteria, magnetic particles were irradiated by a wavelength of 532nm. The photo-thermal effect on the particles was sufficient for extracting DNA, which was consequently utilized for the identification of bacteria. Our device will help monitor the existence of bacteria in various environmental situations such as water, air, and soil.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.8
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• pp.4533-4537
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• 2013

Objective: To use microarray chip technology for screening of stem cell radiation related miRNAs in laryngeal squamous cell carcinoma; study and explore the relationship of miRNAs with radiosensitivity of laryngeal squamous cells. Method: After conventional culture and amplification of the laryngeal squamous carcinoma cell line Hep-2, CD 133+ cells were screened out with combination of isolated culture of stem cell microspheres and FACS for preparation of laryngeal cancer stem cells. After radiation treatment, miRNAs of laryngeal squamous carcinoma stem cells before and after radiation were enriched and purified. After microarray hybridization with mammalian miRNA and scanning of fluorescence signal, the miRNAs of laryngeal squamous carcinoma stem cells before and after radiation was subject to differential screening and clustering analysis. Real-time quantitative RT-PCR was used to verify part of the differentially expressed miRNAs. Results: 70 miRNAs related to laryngeal cancer stem cell radiation with 2-fold difference in expression were screened out, in which 62 were down-regulated and 8 were up-regulated. Fluorescent quantitative RT-PCR results were consistent with miRNAs chip results. Conclusion: Some miRNAs may be involved in self-regulation with laryngeal squamous carcinoma stem cell radiation.

• Korean Journal of Microbiology
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• v.44 no.4
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• pp.346-351
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• 2008

This study develops DNA array which can detect specific sequence of human papilomavirus (HPV) by using lateral flow membrane assay which is usually used for point of care test including pregnant diagnosis. Principle of HPV DNA array is as follow; fixing DNA probe which is peculiar to HPV type 6, 11, 16, 18, 31, 45 on a surface of lateral flow membrane and inducing hybridization response between probe and HPV PCR products which is obtained by using biotin-labeled MY09/l1 primers. And then, we can see the result of DNA hybridization that streptavidin labelled colloidal gold is responded with hybrid biotin. Lateral flow membrane array developed in this study confirms major HPV type economically and conveniently compared with existing HPV DNA chip method.

• Journal of Microbiology and Biotechnology
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• v.14 no.6
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• pp.1239-1248
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• 2004

The methylotrophic yeast Hansenula polymorpha has been extensively studied as a model organism for methanol metabolism and peroxisome biogenesis. Recently, this yeast has also attracted attention as a promising host organism for recombinant protein production. Here, we describe the fabrication and evaluation of a DNA chip spotted with 382 open reading frames (ORFs) of H. polymorpha. Each ORF was PCR-amplified using gene-specific primer sets, of which the forward primers had 5'-aminolink. The PCR products were printed in duplicate onto the aldehyde-coated slide glasses to link only the coding strands to the surface of the slide via covalent coupling between amine and aldehyde groups. With the partial genome DNA chip, we compared efficiency of direct and indirect cDNA target labeling methods, and found that the indirect method, using fluorescent-labeled dendrimers, generated a higher hybridization signal-to-noise ratio than the direct method, using cDNA targets labeled by incorporation of fluorescence-labeled nucIeotides during reverse transcription. In addition, to assess the quality of this DNA chip, we analyzed the expression profiles of H. polymorpha cells grown on different carbon sources, such as glucose and methanol, and also those of cells treated with the superoxide­generating drug, menadione. The profiles obtained showed a high-level induction of a set of ORFs involved in methanol metabolism and oxidative stress response in the presence of methanol and menadione, respectively. The results demonstrate the sensitivity and reliability of our arrays to analyze global gene expression changes of H. polymorpha under defined environmental conditions.

• BMB Reports
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• v.39 no.3
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• pp.247-252
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• 2006

A rapid method for the detection of Hepatitis E Virus (HEV) was developed by utilizing nano-gold labeled oligonucleotide probes, silver stain enhancement and the microarray technique. The 5'-end -$NH_2$ modified oligonucleotide probes were immobilized on the surface of the chip base as the capture probe. The detection probe was made of the 3'-end -SH modified oligonucleotide probe and nano-gold colloid. The optimal concentrations of these two probes were determined. To test the detection sensitivity and specificity of this technique, a conservative fragment of the virus RNA was amplified by the RT-PCR/PCR one step amplification. The cDNA was hybridized with the capture probes and the detection probes on microarray. The detection signal was amplified by silver stain enhancement and could be identified by naked eyes. 100 fM of amplicon could be detected out on the microarray. As the results, preparation of nano-gold was improved and faster. Development time also was shortened to 2 min. Thus, considering high efficiency, low cost, good specificity and high sensitivity, this technique is alternative for the detection of HEV.

• Journal of Microbiology and Biotechnology
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• v.13 no.2
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• pp.317-320
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• 2003

Genome-wide systematic deletion mutants were generated using a PCR-based targeted mutagenesis of Schizosacchaaromyces pombe. In a drug-sensitivity assay using thiabendazole(TBZ), an inhibitor of microtubule assembly, a heterozygous nda2 mutant ($nda2^+/nda2^-$), deleting one copy of nda2 encoding the microtubule subunit alpha1 demonstrated a distinct sensitivity to TBZ, indicating TBZ-induced haploinsufficiency. This result suggests that profiling drug-induced haploinsufficiency can be exploited to identify target genes for drugs and discover new drugs.

• KSBB Journal
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• v.24 no.5
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• pp.432-438
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• 2009

Here, we demonstrated simple nucleic acid, RNA, concentration method using polymer micro chip containing glass bead ($100\;{\mu}m$). Polymer micro chip was fabricated by PDMS ($1.5\;cm\;{\times}\;1.5\;cm$, $100\;{\mu}m$ in the height) including pillar structure ($160\;{\mu}m\;(I)\;{\times}\;80\;{\mu}m\;(w)\;{\times}\;100\;{\mu}m\;(h)$, gap size $50\;{\mu}m$) for blocking micro bead. RNA could be adsorbed on micro glass bead at low pH by hydrogen bonding whereas RNA was released at high pH by electrostatic force between silica surface and RNA. Amount of glass beads and flow rate were optimized in aspects of adsorption and desorption of RNA. Adsorption and desorption rate was measured with real time PCR. This concentrated RNA was applied to amplification micro chip in which NASBA (Nucleic Acid Sequence Based Amplification) was performed. As a result, E.coli O157 : H7 in the concentration of 10 c.f.u./10 mL was successfully detected by these serial processes (concentration and amplification) with polymer micro chips. It implies this simple concentration method using polymer micro chip can be directly applied to ultra sensitive method to measure viable bacteria and virus in clinical samples as well as environmental samples.

• Journal of the Korean Chemical Society
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• v.48 no.5
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• pp.483-490
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• 2004

We have developed a novel polymerase chain reaction (PCR)-microchip gel electrophoresis (MGE) method based on the sieving gel mixture of commercially available poly(vinylpyrrolidone) (PVP) and hydroxy ethyl cellulose (HEC) for the rapid detection and diagnosis of the orf virus (ORFV) from Korean indigenous goat. After amplification of 594-bp DNA fragment from the B2L gene of ORF virus, the amplicon was analyzed by the MGE separation. The glass microfluidic chip (64 mm total length (36 mm effective length)${\times}$90 ${\mu}$m width${\times}$20 ${\mu}$m depth) allowed the fast detection and diagnosis of ORFV in the mixture of 1.0% PVP ($M_r$ 360,000) and 1.0% HEC ($M_r$250,000) as a sieving matrix with better resolution and reproducibility of DNA fragments. Under the electric field of 277.8 V/cm, the 594-bp DNA was analyzed within 4 min. Compared to traditional slab gel electrophoresis, the PCR-MGE method was twenty times faster and an effective clinical method for the quantitative analysis of ORFV.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.40 no.1
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• pp.31-38
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• 1991

A direct digital control technique of a current source using the phase-controlled rectifier is presented. A digital firing technique without sensing the line voltage is proposed. This scheme generates firing pulses directly from error signal between command and output voltage. Thus the phase detection transformers filters and zero-crossing detector are unnecessary. The synchronism is modeled and analized. Also a software synchronization algorithm is presented without a look up table and controls the system in real time with fast dynamic characteristics. Using the single-chip microprocessor 8097BH, the direct digital control is implemented with minimal hardware structure. Using the time-weighted performance index, the optimal discrete IPM control technique is also proposed to control the current of the PCR.