• Biomedical Science Letters
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• v.3 no.2
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• pp.95-105
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• 1997

Currently, the laboratory diagnosis for lyme disease have been performed with the detection of antibodies against Borrelia burgdorferi. However there might be some difficulties in the interpretation of obtained results due to the usage of foreign isolates as an antigen in the test. Therefore the optimization of serological tests with Korean isolates of B. burgdorferi as an antigen would be needed to establish the standardized diagnostic method for the detection of antibodies against B. burgdorferi infection. In this study, the optimization of ELISA was investigated with experimentally challenged rabbit sera and sonicated B. burgdorferi antigens of Korean isolates. Of 217 human patient's sera with unknown fever, the mean seropositivities in ELISA, done under the optimized conditions obtained in this study, were found to be about 8％ against B. burgdorferi sensu late, showing the highest seropositivity of 14.3％ against B. afzelii. In immunoblotting assay with ELISA-positive human sera, the major reactive bands were 41kDa (flagellin) which might be the indication of early infection, and 27kDa, 31kDa (OspA), 34kDa (OspB) which are the characteristics of late infection. Obtained results in this study might strongly indicate the possibility of B. burgdorferi infections in Korea.

• Korean Journal of Food Science and Technology
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• v.40 no.3
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• pp.343-348
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• 2008

The ovomucoid (OM) of egg whites is recognized as a major allergen. Here, the allergenicity of OM in egg whites (EW) treated by chemical, enzymatic, and physiological methods were investigated by competitive inhibitory ELISA using human IgE antibody acquired from egg-allergic patients. Enzymatic hydrolysis, irradiation, and succinic anhydride treatments did not reduce the allergenicity of the OM effectively. Allergenicity was reduced to only 1/20 by deglycosylation with trifluoromethanesulfonic acid (TFMS). Heat treatment of the OM at $121^{\circ}C$ for 10 min reduced allergenicity to 1/100. Furthermore, NaOH (over 3%) treatment reduced allergenicity to 1/10,000, and the combinatory treatment of NaOH (over 0.3%) and heat ($70^{\circ}C$, 15 min) reduced it to less than 1/10,000, which was the most effective method. In this study, which analyzed treated EW using ELISA and patient-derived IgE, the OM allergenicity was nearly the same as its antigenicity according to ELISA using rabbit IgG. However, in the case of the TFMS-treated EW, the antigenicity was much lower than the allergenicity. These results suggest that the allergenicity of OM is slightly different from its antigenicity.

• Korean Journal of Food Science and Technology
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• v.35 no.6
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• pp.1209-1215
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• 2003

This study was carried out to establish a quantitative analysis method of separating immuno-activating substance (EN-SP) from Acanthopanax senticosus (A. senticosus) by competitive direct ELISA. Mouse antiserum (anti-EN-SP) against EN-SP was generated by immunization (s.c.) of EN-SP purified from A. senticosus as an immunogen. The titer of anti-EN-SP was about 1 : 400, and the optimal dilution of EN-SP-HRP conjugate was 1 : 1,000. When the standard curve was constructed by ELISA, its sensitivity was about $0.2{\mu}g/mL$. The coefficient variation of intra- and inter-assay were $6.13{\sim}8.81%$ and $6.73{\sim}8.60%$, respectively. According to the standard curve, the concentration of EN-SP in various senticosus extracts was found to be only $59.85\;{\mu}g$ in 10mg of extract from the bark of A. senticosus. Similarly, the immunostimulating activity to produce $TNF-{\alpha}$ or IL-12 among the various extracts of Acanthopanax was shown to be correlated with the content of EN-SP. These results demonstrated that competitive ELISA was a convenient, fast, reproducible, and accurate method for the determination of EN-SP as an immunologically active standard substance in extract of A. senticosus.

• 한국생물공학회:학술대회논문집
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• 2001.11a
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• pp.829-832
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• 2001

Phage display technique as a new antibody production method can express the protein on the minor coat of phage particle in a library constructed by utilizing a recombination of genes coding the variable regions of immunoglobulin. This new method is particularly advantageous in producing antibodies against toxic substances and compounds with low immunogenicities. We first confirmed the concept of antibody expression on the phage particle by selecting a positive control of the phage library (e.g., Griffin.l donated from MRC center in England). The library was then employed to produce antibodies specific to human serum albumin via repetitive bio-panning procedure. The mean affinity of the antibodies selected gradually increased along with the number of bio-panning, which demonstrated that the phage display method could produce monocloanl antibodies with high affinities.

• Journal of the Korean Chemical Society
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• v.46 no.6
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• pp.535-540
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• 2002

It is very difficult to analyze the microcystins, cyanobacterial toxins quantitatively since it exists in a trace level in lakes. In this paper, two different analytical methods were tried to analyze the microcystins, cyanobacterial toxins quantitatively in water samples collected in Soyang lake. The first method was solid phase extraction method fol-lowed by High Performance Liquid Chromatography(HPLC), and the second method was Enzyme-Linked Immu-nosorbent Assay(ELISA) using the monoclonal antibody of microcystin.

• BMB Reports
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• v.29 no.3
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• pp.192-199
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• 1996

A rapid and sensitive method has been developed to detect a-fetoprotein (AFP) in human serum by a two-site sandwich enzyme-linked immunosorbent assay (ELISA) with monoclonal antibodies (MAbs) for human AFP within 1 h. To obtain the most sensitive and reliable MAbs. 12 kinds of MAbs (HPJ1 to HPJ12) as a capture antibody and 4 kinds of horseradish peroxidase (HRP) conjugated MAbs as a tracer antibody were investigated. Among these, only HPJ 10-HRP conjugated HPJ 1 (HPJ 10-HPJ $1^*$) and HPJ 11-HRP conjugated HPJ 10 (HPJ 11-HPJ $10^*$) were chosen as candidates based on the linearity of the standard curve and the sensitivity of the assay. To further characterize these two pairs. MAbs against human AFP were purified from hybridoma cells. conjugated with HRP. and then characterized to optimize the two-site sandwich ELISA The HPJ 10-HPJ $1^*$ pair showed a sensitivity of 1 ng/ml and a better reproducibility than the HPJ 11-HPJ $10^*$ pair when the human sera were incubated at $37^{\circ}C$ for 30 min. The results obtained for 480 randomly selected human sera showed 0~20 ng/ml of AFP values for the normal human sera. To test the utility of our kit, AFP concentrations were determined for 951 human sera (including 85 normal sera, 480 random blood sera, 213 HBsAg-positives. 50 anti-HCV antibody positives. and 47 malignant diseases) and compared with other commercially available AFP detecting kits. These results show that the present two-site sandwich ELISA method is a rapid, sensitive, and reliable procedure for detecting AFP in human serum.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.23 no.2
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• pp.41-56
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• 2010

Objectives : On an experimental basis, the effects of atopic dermatitis induced materials on the expression of cytokine genes in human monocytes (THP-1, U937) and mast cells were studied. This study was carried out to be considered a fundamental knowledge in the research on the good of oriental medicine. Methods : After culturing THP-1, U937, and HMC-1, with the three different concentrations of LPS ($1\;{\mu}g/ml$), DPE ($10\;{\mu}g/ml$), and DNCB ($1\;{\mu}g/ml$), atopic dermatitis induced materials were treated in the culture medium. To investigate cytokine genes expression patterns, with lysis buffer and separation reagent, total RNA was extracted from THP-1, U937, and HMC-1 at intervals of 0, 12, 24, and 48 hours. Both cytokine mRNA expression patterns by atopic dermatitis induced materials and change of cytokine genes expression patterns in relation to atopy by selenium were analyzed with RT-PCR. Also IL-4 and INF-$\gamma$, which were secreted in the HMC-1, were analyzed using ELISA method. Results : 1. After treating THP-1 and U937 with LPS, DPE, and DNCB, there was no significant change in cytokine genes themselves, but various cytokines (IL-4, IL-6, IL-8, IL-13, IFN-$\gamma$, IFN-a, MCP-1, B2-MG) were expressed. 2. In the case of HMC-1, the expressions of IL-6 and IL-8 were significantly increased in the analysis of mRNA expression by dust mite allergens in DPE. 3. As a result of ELISA method, it is certain that IL-4 and IFN-$\gamma$ protein were secreted in the HMC-1 by DPE. 4. Selenium, an essential trace element, decreased the IL-10 and IL-13 expression in the HMC-1 by DPE. Conclusion : The results suggest that it is necessary to choose proper atopic dermatitis induced materials and suitable cultured cells in establishment of in vitro model of atopic dermatitis.

• Environmental Analysis Health and Toxicology
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• v.5 no.3_4
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• pp.29-36
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• 1990

Aflatoxins, produced by strains of Aspergillus flavus and Aspergillus parasiticus, can be found worldwide in corn, barley, peanuts, and other commodities. Among this group of toxins, aflatoxin B$_1$was realized to be one of the most potent environmental carcinogens, mutagens and teratogens. It is routinely monitored by methods such as thin layer chromatography, liquid chromatography, fluorodensitometric technique and radioimmunoassay. However, these assays are expensive, necessitate radioactive reagents, and require overnight incubation. In this study, the determination of fungal flora in several sorts cereals has been carried out in order to obtain an appropriate information of the population of fungi. The quantitative analysis of aflatoxin B$_1$has been carried out by High Performance Liquid Chromatography (HPLC) method and Enzyme Linked Immunosorbent Assay (ELISA). The results were summarized as follow: 1) From the 100 samples,313 colonies of fungi were isolated. Among the 313 colonies, 274 were possible to identify into 11 genera. The identified genera were Aspergillus Penicillium, Mucor, Rhizopus, Alternaria, Cladosorium, Fusarium, Circinella, Chrysosporium, Paecilomyces and Phoma. 2) Six of Aspergillus flavus were aflatoxin-producing strains. Aspergillus flavus isolated from sample barleys was contained the highest content (21.8 $\mu\textrm{g}$/ml) of aflatoxin B$_1$. 3) The yield of aflatoxin B$_1$-oxime compound was appromately 75%. Aflatoxin B$_1$-oxime-Human serum albumin was approved by formal consent as complete antigen. 4) Direct competitive ELISA permitted detection of 0.15 ng levels. In the quantitative microanalysis, ELISA was superior to HPLC method.

• Korean Journal of Poultry Science
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• v.18 no.3
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• pp.183-196
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• 1991

In order to establish ELISA method to detect antibody against IBV various factors involved were examined. Antigen was prepared from Massachusetts type IBV which is known to be one of serotypes distributed most widely. The virus was grown in embryonated SPF chicken eggs. Allantoic fluid harvested was processed to ultracentrifugation and sucrose density gradient centrifugation to produce a purified antigen The antisera selected from the field samples based on hemagglutination inhibition test were used as the standard positive and negative sera for this study and the results obtained were summarized as follows. 1 , It was found that ELISA test was satisfactory when the purified antigen was coated on the plate in the amount of about 40ng protein per well. In case of the phospholipase treated hemagglutinating antigen it gave satisfactory results when the each well wns coated with 1.2 to 2.5 hemagglutinating unit which was equivalent to 40 to 90ng of protein. 2. There was no significant difference in the ratio of optical density of positive to that of negative serum whether the coated antigen was held for 1 hour at 37$^{\circ}C$ or it was held overnight at 4$^{\circ}C$. The coated antigen could be kept in dried state without change of antigenecity for at least one month of experimental period at 4$^{\circ}C$. 3. There was a big variation in the optical density and P/N values depending on the maker of the plates and on the plate of the same maker. 4. It was found that background optical density was negligible when serum was diluted more than 1：50 and serum dilution of 1：100 appeared to be appropriate as a routine test dilution to screen the antibody. 5. Optical density was fairly constant 15 minutes afterward from the time substrate was treated and during the 4 hours after stopper was treated. 6. There was a low correlation(r＝0.42) between ELISA and HI test. However, when 74serum samples were tested for the IBV antibody, 98.7% were found to be positive by both tests in which titers of 2$^{6}$ or more by HI test and P/N values of 1.4 or more by ELISA were considered to be positive, 7 Day-old IBV vaccinated chickens shows a similar antibody decay and rising pattern until 8 weeks of age by the two tests, ELISA and HI.

• Journal of Environmental Health Sciences
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• v.27 no.4
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• pp.35-40
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• 2001

In order to evaluate the safety of agricultural products in Korea, we carried out work by screening of Fusarium species. which can produce deoxinivalenol(DON) from agricultural products in Western Gyeongnam, Korea. From 215 samples of soil agricultural products, 129 strains of Fusarium species were obtained. The production of DON was verified by thin layer chromatography(TLC) As the results of TLC, 25 strains were identified as DON producing strain. But only 10 strains were identified as DON producing strains by enzyme-linked immunosorbent assay (ELISA). The maximum DON producing strain No.41 was isolated from corn. In conclusion. the above results indicate that DON producing fungi contaminated agricultural products in Korea. Therefore further studies are required to accumulate more detailed data about the contamination of DON in various agricultural products.