• Environmental Mutagens and Carcinogens
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• v.16 no.2
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• pp.88-96
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• 1996

Fluorescence in situ hybridization (FISH) with the DNA probe for human chromosome 4 was used to analyse in vitro radiation induced chromosome rearrangement in peripheral lymphocyte. Translocations, dicentrics, acentrics and color junctions involving the painted chromosome were scored according to the Protocol for Aberration Identification and Nomenclature Terminology (PAINT) system. The frequency of chromosome rearrangements including reciprocal translocation, dicentric, acentric fragment and color junction increased with radiation dose. The frequency of dicentric chromosome reduced by the fixation time following irradiation, whereas that of translocation was relatively persistent. The applicability of FISH for scoring stable translocation for biological dosimetry was demonstrated.

• 한국생물공학회:학술대회논문집
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• 2001.11a
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• pp.282-285
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• 2001

The microbial community structure and in situ spatial distribution of ammonia oxidizing and nitrite oxidizing bacteria in nitrifying biofilm of an upflow biological aerated filter system were investigated. The reactor had been continuously operated under high free ammonia concentration and low DO concentration for nitrite accumulation more than 2 years before the experiment. Fluorescence in situ hybridization

• Molecular & Cellular Toxicology
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• v.2 no.1
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• pp.60-66
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• 2006

Methylmercury (MeHg), one of the heavy metal compounds, can cause severe damage to the central nervous system in humans. Many reports have shown that MeHg is poisonous to human body through contaminated foods and has released into the environment. Despite many studies on the pathogenesis of MeHg-induced central neuropathy, no useful mechanism of toxicity has been established so far. This study, using of suppression subtractive hybridization (SSH) method, was peformed to identify differentially expressed genes by MeHg in SH-SY5Y human neuroblastoma cell line. We prepared to total RNA from SH-SY5Y cells treated with solvent (DMSO) and $6.25\;{\mu}M\;(IC_{50})$ MeHg and performed forward and reverse SSH. Differentially expressed cDNA clones were screened by dot blot, sequenced and confirmed that individual clones indeed represent differentially expressed genes with real time RT-PCR. These sequences were identified by BLAST homology search to known genes or expressed sequence tags (ESTs). Analysis of these sequences may provide an insight into the biological effects of MeHg in the pathogenesis of neurodegenerative disease and a possibility to develop more efficient and exact monitoring system of heavy metals as ubiquitous environmental pollutants.

• Korean Journal of Food Science and Technology
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• v.34 no.5
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• pp.856-861
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• 2002

Surface-modified powders were produced by hybridization system using core freeze-dried lactic acid bacteria (Lactobacillus acidophilus ATCC 43121) and enteric coating materials. Scanning electron microscopy showed that the surface of freeze-dried lactic acid bacteria changed to smooth round shape during surface reforming process, although no significant physical damages affecting the activity of the lactic acid bacteria were observed based on viability and salt-tolerance tests. Signigicant difference was not found in acid tolerance test probably due to the inherent acid tolerance of L. acidophilus ATCC 43121. Significantly improved heat tolerance was obtained by surface modification process. Among the tested coating materials, Sureteric showed a higher surface- reforming ability than Eudragit S100 and L100-55. Core : coating ratio agent of 9 : 1 (w/w) with rotor speed of 15,000 rpm for 3 min were determined to be optimum conditions for the process.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2001.11a
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• pp.150-154
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• 2001

• Korean Journal of Veterinary Research
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• v.37 no.4
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• pp.793-807
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• 1997

We tried to develop detection system of porcine reproductive and respiratory syndrome virus(PRRSV) by in situ hybridization(ISH) in the piglets experimentally infected with KPRRS-2, the Korean isolate(12 piglets) or Mn-1b, the American isolate(4 piglets), and in the natural infection suspected 6 piglets. Twelve 30-days-old piglets(two pigs per each inoculated group) were inoculated by nasal instillation of KPRRS-2 virus(total dose $10^{4.5}TCID_{50}$), Six piglets(one pig per each group) were induced contact infection with inoculated piglets, during the experiment, and two piglets were used as control. Inoculated or contacted piglets were euthanized at 1, 3, 5, 7, 14 and 21 days postinoculation(DPI). The respiratory signs such as coughing and nasal discharge were observed on day 3 DPI, and ear cyanosis were on day 5 DPI, including contacted piglets. Through the necropsy, purple discolorization of dorsal part of lung, and hypertrophy of local lymph nodes were observed. The histopathological lesions of lung were interstitial pneumonia characterized by type 2 pneumocyte hyperplasia. We prepared the probe for ISH by RNA isolation from KPRRS-2, RT-PCR, and biotin labeling. We performed the ISH within only 1~2 hours using $Microprobe^{TM}$ capillary action system. As the results, the strong red specific positive signals, means PRRSV distribution, was mainly observed in the cytoplasm of alveolar macrophages. And also signals were detected in some type 2 pneumocytes and bronchiolar epithelium of lung, myocardium, liver, kidney, tonsil, spleen, gastrointestinal mucosa, testis and lymph nodes.

• Korean Journal of Veterinary Research
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• v.39 no.1
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• pp.148-158
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• 1999

The purpose of this study was to establish a rapid, reliable diagnostic method detecting Encephalomyocarditis virus(EMCV) RNA in formalin-fixed, paraffin-embedded tissues of EMCV naturally infected pigs by cDNA probe of EMC $K_3$, the EMCV strain isolated from Korea. Using a biotin-labelled nick translated probe for the cDNA marker. We made up for some defects of radiolabeled method. In sits hybridization(ISH) technique, differently from the other nucleic acid hybridization methods, is able to detect the virus genome specifically in the state of the intact shapes of cells and/or tissues. We succeeded in performing the experiment to detect the EMCV within 1~2 hours using the $MicroProbe^{TM}$ capaillary action system. In this study, we observed highly specific positive signals of red color by staining the paraffin-embedded tissue sections of naturally EMCV-infected pig organs or tissues, including brain, heart, kidney and lacrimal gland with the Fast Red TR salt/Naphtol phosphate chromogen. The results suggested that this ISH method is considered as a highly sensitive and reliable tool for molecular biologic diagnosis of the EMC viral disease.

• Journal of Microbiology and Biotechnology
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• v.20 no.10
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• pp.1463-1470
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• 2010

E. coli has long been widely used as a host system for the manufacture of recombinant proteins intended for human therapeutic use. When considering the impurities to be eliminated during the downstream process, residual host cell DNA is a major safety concern. The presence of residual E. coli host cell DNA in the final products is typically determined using a conventional slot blot hybridization assay or total DNA Threshold assay. However, both the former and latter methods are time consuming, expensive, and relatively insensitive. This study thus attempted to develop a more sensitive real-time PCR assay for the specific detection of residual E. coli DNA. This novel method was then compared with the slot blot hybridization assay and total DNA Threshold assay in order to determine its effectiveness and overall capabilities. The novel approach involved the selection of a specific primer pair for amplification of the E. coli 16S rRNA gene in an effort to improve sensitivity, whereas the E. coli host cell DNA quantification took place through the use of SYBR Green I. The detection limit of the real-time PCR assay, under these optimized conditions, was calculated to be 0.042 pg genomic DNA, which was much higher than those of both the slot blot hybridization assay and total DNA Threshold assay, where the detection limits were 2.42 and 3.73 pg genomic DNA, respectively. Hence, the real-time PCR assay can be said to be more reproducible, more accurate, and more precise than either the slot blot hybridization assay or total DNA Threshold assay. The real-time PCR assay may thus be a promising new tool for the quantitative detection and clearance validation of residual E. coli host cell DNA during the manufacturingprocess for recombinant therapeutics.

• 한국생물공학회:학술대회논문집
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• 2001.11a
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• pp.827-828
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• 2001

We developed a geno-chromatographic assay system based on hybridization between target DNA (e.g., amplified product from PCR) and a capture probe immobillized on a predetermined site of membrane. This system can offer a rapid detection of a gene sequence specific to a certain type of cells as well as simplicity of the analytical procedure. Such performances were demonstrated by utilizing Salmonella typhimurium as model analyte.

• Korean Journal of Veterinary Research
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• v.42 no.3
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• pp.351-362
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• 2002

Newcastle disease (ND) is a highly contagious infection of poultry, Two pathology-based techniques, in situ RT-PCR and in situ hybridization (ISH) were applied to formalin-fixed, paraffin-embedded tissues from chickens naturally infected with velogenic ND virus (VNDV). Two pairs of primers and a probe for ISH and in situ RT-PCR, respectively, were selected from highly conserved region of matrix gene of NDV. The ISH experiment was carried out using MicroProbe$^{TM}$ capillary action system within 2 hours. In situ RT-PCR was performed using MicroProbe$^{TM}$ capillary action system and GeneAmp In Situ PCR system. With ISH and in situ RT-PCR, viral nucleic acid was detected in the central nervous system of chickens from infected with neurotropic velogenic Newcastle disease virus (NVNDV), whereas viral nucleic acid was detected in various organs or tissues of chickens from infected with viscerotropic velogenic Newcastle disease virus (VVNDV). In the NVND group, positive signals were characteristically defined in the cytoplasm of neuron, vascular endothelial cells, and perivascular mononuclear macrophages in the central nervous system. One of NVND group, chicken from one farm exhibited positive signals in the bronchial epithelium. The VVND group chickens showed positive reaction in the macrophages, vascular endothelium, and bronchiolar epithelium. Markedly, viral nucleic acid was detected in the macrophages of morphologically normal tissues which were peripheral or located in distant areas from lesions. The central nervous system of chickens infected with VVND virus had positive signals in the vascular endothelial cell, perivascular mononuclear macrophages and some neuron. The number and intensity of the positive cells by in situ RT-PCR were more and stronger, respectively, in comparison with those by ISH. Particularly, positive reaction was detected in macrophages infiltrating in cardiac muscle by in situ RT-PCR, but not obtained by ISH. Therefore, these results demonstrated that ISH is a rapid diagnostic method for detection of NDV and in situ RT-PCR can be used as an efficient method for detection of low viral load infection or subclinical viral infection of NDV.