• Proceedings of the Korean Vacuum Society Conference
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• 2013.08a
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• pp.268.2-268.2
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• 2013

Nanogap interdigitated electrodes (NIDEs) can serve as an alternative platform for the biomolecular detection [1]. In this work, the NIDEs were adopted in a simple and sensitive detection of Pneumococcal surface protein A (PspA). The NIDEs were fabricated by the combination of photo and chemical lithography. Photolithographically-defined initial gap of about 200 nm was narrowed down to a few tens of nanometers by surface-initiated growth of the initial electrodes (chemical lithography) [2]. Bare silicon oxide surface between the electrodes was chemically modified to immobilize capturing antibodies and, after exposure to the samples, the device was immersed in a solution containing the probe-antibody-conjugated Au nanoparticles (Au NPs). The conductance change accompanied with the Au NP immobilization was interpreted as the existence of PspA. Detection limit of the measurements and further improvement of the detection efficiency were discussed with the results from I-V analysis, scanning electron microscopy, and atomic force microscopy.

• Research in Plant Disease
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• v.20 no.3
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• pp.173-181
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• 2014

The early and accurate detection of plant viruses is an essential component to control those. Because the globalization of trade by free trade agreement (FTA) and the rapid climate change promote the country-to-country transfer of viruses and their hosts and vectors, diagnosis of viral diseases is getting more important. Because symptoms of viral diseases are not distinct with great variety and are confused with those of abiotic stresses, symptomatic diagnosis may not be appropriate. From the last three decades, enzyme-linked immunosorbent assays (ELISAs), developed based on serological principle, have been widely used. However, ELISAs to detect plant viruses decrease due to some limitations such as availability of antibody for target virus, cost to produce antibody, requirement of large volume of sample, and time to complete ELISAs. Many advanced techniques allow overcoming demerits of ELISAs. Since the polymerase chain reaction (PCR) developed as a technique to amplify target DNA, PCR evolved to many variants with greater sensitivity than ELISAs. Many systems of plant virus detection are reviewed here, which includes immunological-based detection system, PCR techniques, and hybridization-based methods such as microarray. Some of techniques have been used in practical, while some are still under developing to get the level of confidence for actual use.

• Korean Journal of Veterinary Service
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• v.16 no.2
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• pp.111-119
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• 1993

In this study, we carried out the rapid diagnostic system based on indirect fluorescent anti-body technique (IFAT) for detection of bacterial diseases in cultured freshwater fishes. 1. When the fishes were tested with graded dilution of Edwardsiella tarda FPC 470 bacteria detection from ten fishes Injected with $4.1{\times}10^3$colony forming unit(CFU) /ml, all of them were detected by IFAT but only two fishes were recognizable by the culture method in the tested fishes injected with $4.1{\times}10^3$CFU /ml. 2. The bacteria E. tarda could be detected by IFAT method from 1 to 48hrs after Injection in the tissues tested such as kidney, liver and spleen of the fishes, whereas detection by culture method could be recognized from 1 to 48hrs after injection In the kidney and spleen but it was not possible from preinjection to 1 hr in the liver. 3. Thus, IFAT proved to be more useful technique than plate culture method in the diagnosis of Edwardsiellosis in the freshwater fishes.

• Journal of Microbiology and Biotechnology
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• v.20 no.8
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• pp.1179-1184
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• 2010

We report the generation of the first monoclonal antibody that specifically binds to the polysaccharide chitosan. Mice were immunized with a mixture of chitosans, and hybridoma clones were screened for specific binders, resulting in the isolation of a single clone secreting a chitosan-specific IgM, mAbG7. In ELISAs, the antibody could bind to chitosans of varying composition, but demonstrated the highest affinity for chitosans with lower degrees of acetylation (DA) and very poor binding to chitin. We tested the ability of the antibody to bind to chitosan in situ, using preparations of fungal cell walls. Immunofluorescence microscopy confirmed that the antibody bound strongly to the cell walls of fungi with high levels of chitosan, whereas poor staining was observed in those species with cell walls of predominantly chitin or cellulose. The potential use of this antibody for the detection of fungal contamination and the protection of plants against fungal pathogens is discussed.

• Korean Journal of Veterinary Service
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• v.27 no.1
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• pp.89-94
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• 2004

Total 2,451 sera collected from pig farms nationwide were tested for the detection of porcine reproductive and respiratory syndrome(PRRS) virus antibodies. The results were analyzed between different geographic regions, types of breeding pigs, and different years. The overall seroprevalence of PRRS virus antibodies for 3 years was 32.4%(705/2,451). The seroprevalence of PRRS virus antibodies in years 2000, 2001, 2002, and 2004 was 33.4% (284/850), 38.6%(291/754), 33.3%(155/466), and 17.1%(65/381), respectively. The seropevalence of PRRS virus antibody in sow in years 2000, 2001, 2002 and 2003 was 31.7%, 28.4%, 29.6%, and 13.4%, respectively. The seropevalence of PRRS virus antibody in gilts in years 2000, 2001, 2002 and 2003 was 36.6%, 67.4%, 54.7%, and 33.9%, respectively. The seropevalence of PRRS virus antibody in boars in years 2000, 2001 and 2003 was 45.7%, 36.4%, and 100%, respectively. No boar serum sample was submitted for the diagnosis of PRRS virus antibody in the year 2000. High seroprevalence of the PRRS virus antibody in sow, gilts and boars indicates that the infected breeding pigs are the major source of the PRRS virus infection, and also play an important role in spreading the PRRS virus between fan mates or herds.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.30 no.6
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• pp.948-955
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• 1997

Immunomagnetic separation of virus coupled with .reverse transcription-polymerase chain reaction (IMS-PCR) was performed with infectious hematopoietic necrosis virus (IHNV). A DNA fragment of expected size was synthesized in the RT-PCR with total RNA extracted from IHNV inoculated CHSE-214. In a SDS-PAGE analysis, a protein band of over 70kDa was detected from non-infected cells and cells inoculated with IHNV and infectious pancreatic necrosis virus (IPNV). This protein was detected in the Western blot analysis probably because of non-specific reaction to monoclonal antibody against IHNV nucleocapsid protein. In the immunomagnetic separation, magnetic beads coated with monoclonal antibody against the IHNV nucleocapsid protein was incubated with supernatant from IHNV inoculated CHSE-214 cells. During this process, the non-specifically reacting protein could be removed by washing the magnetic bead with PBS in the presence of an external magnetic field, and viral proteins were detected from the remaining, cleaned magnetic beads. It was necessary to extract viral RNA from the captured virus particles before RT-PCR, and no DNA product was detected when the captured virus was only heated 5 min at $95^{\circ}C$. A PCR-product of expected size was synthesized from IMS-PCR with magnetic beads double coated either by goat anti-mouse IgG antibody -monoclonal antibody or streptavidin - biotin conjugated monoclonal antibody.

• 대한치주과학회:학술대회논문집
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• 2001.12a
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• pp.97-97
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• 2001

• Bulletin of Food Technology
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• v.23 no.2
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• pp.168-176
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• 2010

• Korean Journal of Veterinary Service
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• v.24 no.4
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• pp.343-346
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• 2001

During the period of January to December 2000, a total of 3,505 swine sera was collected from 208 farms, which are located throughout country, for the diagnosis of porcine reproductive and respiratory syndrome(PRRS). The antibody to porcine reproductive and respiratory syndrome virus(PRRS) was tested by indirect immunofluorescent antibody(IFA) test. Of 208 farms tested, at least one or more than one pigs was positive for PRRSV antibody in 188(90.4%) farms. The overall seroprevalence of PRRSV antibody was 45.1% (1581/3505). Most pigs were infected with PRRSV at around 50- to 60-day old. The seroprevalence of antibody varied with age. The highest seroprevalence of PRRSV antibody was observed in the growing pigs at around 80-day old. About one-thirds of adult pigs including boar, gilt and sow were positive to PRRSV antibody. In many farms, the infection of PRRSV was chronic and confined to grower and/or finisher. However, antibody was detected from all production phase in some farms.

• Journal of Food Hygiene and Safety
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• v.8 no.4
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• pp.205-214
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• 1993

The monoclonal antibody to chloramphenicol(CAP) was produced to develop an enzyme-linked immunosorbent assay(ELISA) for residual CAP. An immunogen(CAP-BSA) was prepared by immunogen, antibody titer was measured by indirect ELISA. Spleen cells form the immunized mouse were fused with SP2/OAg14 myeloma cells. Among hybridomas selected in HAT media, 6 clones shown high antibody titer to CAP were subjected to cloning by limit dilution, and all of the monoclonal antibodies(MCA1, 2, 3, 4, 5, 7 and 9) produced by each clone were identified as IgG1 by ELISA isotyping analysis. Competitive ELISA condition was established by using the purified monoclonal antibody MCA1 as primary antibody and CAP-HSA conjugate as coating antigen. Standard curve of CAP(n=28) showed that the lowest detection limit of CAP is 20ng/ml level. The cross-reactivities of the 6 monoclonal antibodies showed that CAP sodium succinate. CAP base, P-nitrophenol, and p-nitrobenzyl alcohol were 89∼178, 0.050∼2.237, 0.056∼0.794 and 0.013∼7.939%, respectively. No cross-reactivities were observed with phenylalanine, tyrosine, glutamine, thiamphenicol, neomycin, streptomycin, gentamicin, sulfamethazine, sulfathiazole, chlortetracycline and p-aminobenzoic acid.