• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.133.1-133
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• 2003

Gummy stem blight, caused by Didymella bryoniae occurs exclusively on cucurbits. This fungus has been known not to produce its pycnidium in vitro unless irradiated. Through this study, we optimized cultural conditions for mass-production of pycnidiospore by Metal Halide Lamp irradiation. In brief, the mycelial was cultured at $26^{\circ}C$ on PDA, for 2 days under the darkness, and then the plate was illuminated with MH lamp continuously for 3-4 days at $26^{\circ}C$, a great number of pycnidia was simultaneously formed. Thus produced pycnidiospores were used as immunogen. From fusions of myeloma cell (v-653) with splenocytes from immunifed mice were car ried out. And, two hybridoma cell lines that recognized the immunogen Didymella bryoniae were obtained. One Monoclonal Antibody, Db1, recognized the supernatant and the other monoclonal antibody, Db15, recognized the spore. Two clones were selected which were used to produce ascite fluid two MAb Db1 and Db15, were immunotyped and identified as IgG1 and IgG2b, respectively. Titer of MAb Db1 and MAb Db15 was measured absorbance exceeded 0.5 even at a $10^{-5}$ dilution. The MAbs reacted positively with Didymella bryoniae but none reacted with other of fungi and CMV, CGMMV Sensitivity of MAb was precise enough to detect spore concentration as low as $10^{3}$ well by indirect ELISA characterization of the MAb Db1, Db15 antigen by heat and protease treatments show that the epitope recognized by the MAb Bb1, Db15 were a glycoprotein.

• Microbiology and Biotechnology Letters
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• v.20 no.3
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• pp.301-310
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• 1992

This work was performed to investigate the possibility of using J96 hemolysin(Hly, Hly A) vaccine against urinary tract infecting Escherichia coli. Based on the known sequence of J96 hemolysin which was originally isolated from a pyelonephritis patient, ten 20-mer oligonucleotide probes were synthesized. Radioactive labelled 8 probes showed positive colony blots against most of the hemolysin producing wild type E. coli, while HA484 and HA661 showed 28.3, 71.7% positive blots, respectively. This result means that hemolysin genes are highly conserved. Also, 12 anti-Hly MABs(monoclonal antibodies) showed more than 90% positive immunoblots against secreted hemolysin from wild type E. coli. Especially, the result that MAB132 neutralized hemolysin from all of the wild type E. coli augments the idea that hemolysin will be effective as a vaccine.

• Journal of Microbiology and Biotechnology
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• v.26 no.8
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• pp.1457-1463
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• 2016

Vibrio anguillarum, a devastating pathogen causing vibriosis among marine fish, is prevailing in worldwide fishery industries and accounts for grievous economic losses. Therefore, a rapid on-site detection and diagnostic technique for this pathogen is in urgent need. In this study, two mouse monoclonal antibodies (MAbs) against V. anguillarum, 6B3-C5 and 8G3-B5, were generated by using hybridoma technology and their isotypes were characterized. MAb 6B3-C5 was chosen as the detector antibody and conjugated with quantum dots. Based on MAb 6B3-C5 labeled with quantum dots, a modified dot blot assay was developed for the on-site determination of V. anguillarum. It was found that the method had no cross-reactivity with other than V. anguillarum bacteria. The detection limit (LOD) for V. anguillarum was 1 × 10³ CFU/ml in cultured bacterial suspension samples, which was a 100-fold higher sensitivity than the reported colloidal gold immunochromatographic test strip. When V. anguillarum was mixed with turbot tissue homogenates, the LOD was 1 × 10³ CFU/ml, suggesting that tissue homogenates did not influence the detection capabilities. Preenrichment with the tissue homogenates for 12 h could raise the LOD up to 1 × 10² CFU/ml, confirming the reliability of the method.

• Journal of Life Science
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• v.8 no.6
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• pp.695-701
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• 1998

This study was carried out to investigate levels of the components of microsomal mixed function oxidase (MFO) system and activities of the hepatic microsomal cytochrome P45O (P45O)-dependent monooxygenases of grass snake (Natrix tigrina Lateralis) and to compare with those of rat. The levels of P45O and cytochrome b$_{5}$, (b$_{5}$) of snake were much lower than those in rat. NADPH-cytochrome c reductase activity in the snake was also only 40% of that in the rat. Activities of 7-ethoxycoumarin 0-deethylase (ECOD) and benzphetamine N-demethylase (BPDM) of snake hepatic microsomes, when compared with those of rat, were markedly low. But, aryl hydrocarbon hydroxylase (AHH) and testosterone hydroxylase (TSH) activities were nearly the same or higher than those of the rat. Of the P45O-dependent TSHs measured, 7$\alpha$-hydroxylase activity was the highest in snake, whereas, 6$\beta$-hydroxylase activity was the highest in rat. However, stereoselectivity of the enzyme from the snake to C2 and C6 positions of testoste-rone was the same as rat. The result of radioimmunoassay (RIA) for the identification of five P45O isozymes with MAbs shows that relatively high content of ethanol-inducible P45O isozyme, CYP2El, exists in the rat, whereas MC-inducible P45O isozyme, CYP2A1/1A2, does in the snake. From the analyses of SDS-PAGE and RIA of partially pu-rified P45O, we suggest the possibility of the presence of a certain P45O isozyme(s) in hepatic microsomes of snake different from those of rat.

• Korean journal of applied entomology
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• v.57 no.1
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• pp.7-13
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• 2018

Currently, there is no available tool that rapidly diagnoses pine wood nematode (PWN)-infected pine trees in the field. In this study, we synthesized and purified PWN Galectin, which might be an antigen specific to PWN, using the Baculovirus expression system. We used PWN Galectin as an antigen for generating 1,464 fusion hybridoma cell lines secreting monoclonal antibodies (Mabs). Among them, we selected 62 fusion hybridoma cell lines showing high reactivity to PWN Galectin. We further selected 12 fusion hybridoma cell lines showing high reactivity to the standard PWN-infected pine tree phosphate buffered saline (PBS) extract. Additionally, two fusion hybridoma cell lines showing no or extremely low reactivity were used as controls. The selected fusion hybridoma cell lines were subjected to limiting dilutions for selecting and establishing Mab-secreting cell lines showing higher reactivity to the standard PWN-infected pine tree extract than to the standard normal pine tree PBS extract. Moreover, the selected fusion hybridoma cell lines were further selected based on their higher reactivity to PWN protein extracts than to three non-pathogenic nematode protein extracts. The Mab-secreting cell lines established in this study could be used to develop rapid diagnostic tools that can be used in the field or in laboratories for detecting PWN-infected pine trees or PWN.

• Journal of Food Hygiene and Safety
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• v.31 no.1
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• pp.21-27
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• 2016

The objectives of this study are to produce monoclonal antibodies (MAbs) against Vibrio parahaemolyticus and to develop an immuno-selective filtration (ISF) method for the rapid and sensitive detection of V. parahaemolyticus. The characterization of the MAb produced from HKVP 4H9-9 hybridoma cell was validated by enzyme-linked immunosorbent assay (ELISA) and western blot. The produced MAb was specific to V. parahaemolyticus and showed weak cross-reaction to V. alginolyticus, V. vulnificus and Staphylococcus aureus. After optimization of the method, $5{\times}10^1cell/mL$ of V. parahaemolyticus in a pure culture could be detectable. Although weak cross-reactivity to V. vulnificus, V. alginolyticus and Staphylococcus aureus was observed, the ISF was confirmed to be highly specific to V. parahaemolyticus. Especially, the ISF showed the most sensitivity compared to the immunoassays currently reported is easier to perform and quicker than ID-ELISA.

• Food Science and Biotechnology
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• v.16 no.4
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• pp.515-519
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• 2007

Rapid immunochromatographic assay (ICA) kits were developed using flagella-specific monoclonal antibodies (MAbs) and rabbit polyclonal antibodies for screening Listeria spp. in food. The establishment of different formats, MAb 2B1 as capture antibody and MAb 7A3 or rabbit polyclonal antibodies as detector antibody, was compared. The 2 formats of the ICA kit were shown to have specific reactions with Listeria and no cross-reactivity with any of the non-Listeria including Escherichia coli O157:H7 and Salmonella enteritidis. The detection limits of the ICA kit using the combination of gold-labeled MAb 7A3 and MAb 2B1 showed $1{\times}10^5$ and $1{\times}10^6\;CFU/0.1\;mL$ at 22 and $30^{\circ}C$, respectively. The other format of the ICA kit using the combination of gold-labeled rabbit polyclonal antibodies and MAb 2B1 showed $1{\times}10^6\;CFU/0.1\;mL$ at $22^{\circ}C$ but weak signal at 30 culture. The format utilizing MAb was more sensitive than the one using polyclonal antibodies for capture antibody. Samples contaminated with L. monocytogenes 4b culture (9-10, 5-6, and 1-2 CFU/mL) on pork and pasteurized milk were confirmed as positive results. Current data suggests that this ICA kit is a rapid, simple and effective tool to screen for Listeria spp. in food.

• Journal of Food Hygiene and Safety
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• v.33 no.3
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• pp.185-192
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• 2018

The purpose of this study was to develop an indirect enzyme-linked immunosorbent assay (indirect ELISA) based on a monoclonal antibody (MAb) that is specific to mackerel thermal stable-soluble protein (TSSP), that can be used for the rapid detection of mackerel in processed marine foods. Among the four MAbs (3A5-1, 2, 9, and 12) developed in previous studies, the 3A5-2 MAb that showed high specificity and sensitivity were selected and used to develop the indirect ELISA method. The detection range of the indirect ELISA was 0.02%-0.001% and the detection limit of 0.001% was shown. No cross-reaction to other marine products and food ingredients was observed by the indirect ELISA. Processed marine foods containing mackerel with ${\geq}0.3$ O.D. value at 405 nm were estimated as positive samples by the indirect ELISA. Therefore, the indirect ELISA can be used as a rapid and sensitive method to identify mackerel authenticity and adulteration in processed marine foods.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.16 no.10
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• pp.941-950
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• 1991

channel is severely degraded by multipath delay time spread. In this paper. We propose a simple multipath delay time detection method, which has a merit of in serviceable, yet simple H/W realizability for $\pi/4$ shift QPSK by detecting cross channel interference. A $\pi/4$ shift QPSK signal originally has quadrature channel(Q-ch) component. Thus in order to measure CCI between in-phase channel(I-ch) and quadrature channel(Q-ch), which closely related to multipath delay time, Frequency doubling scheme(frequency doubler) and differential detector is proposed, which makes $\pi/4$ shift QPSK signal look like BPSK and also makes it possible for CCI to be detected at I-ch detector output. To get an information from time varying I-ch output signal under the multipath lading environment, a method for obtaining the mean of the absolute value$(V_{MABS}(t))$ and another one for obtaining the root mean square value$(V_{RMS}(t))$ of CCI are proposed. Furthermore, a relationship between delay spread and CCI is also analyzed. In order to confirm theoretical results, computer simulation has been carried out under the quasi-static and Reyleigh distributed two ray multipath fading environments. A fairly good result was obtained. However it was also shown that this method is sensitive to bandwidth restriction to some extent. In addition, some idea for a simple hardware realization for the frequency doubler are given.