• Food Science of Animal Resources
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• v.34 no.5
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• pp.717-723
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• 2014

A rapid and specific PCR assay for the simultaneous detection of Listeria monocytogenes, Escherichia coli O157:H7, Bacillus cereus, Salmonella spp., and Staphylococcus aureus in foods was developed to reduce the detection time and to increase sensitivity. Multiplex PCR developed in this study produced only actA, fliC, hbl, invA, ileS amplicons, but did not produce any non-specific amplicon. The primer sets successfully amplified the target genes in the multiplex PCR without any non-specific or additional bands on the other strains. The multiplex PCR assays also amplified some target genes from five pathogens, and multiplex amplification was obtained from as little as 1 pg of DNA. According to the results from the sensitivity evaluation, the multiplex PCR developed in this study detected 10 cells/mL of the pathogens inoculated in milk samples, respectively. The results suggested that multiplex PCR was an effective assay demonstrating high specificity for the simultaneous detection of five target pathogens in food system.

• Research in Plant Disease
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• v.24 no.4
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• pp.348-352
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• 2018

A multiplex reverse transcription-polymerase chain reaction (mRT-PCR) assay was developed for the detection of Clover yellow vein virus (ClYVV), Peanut mottle virus (PeMoV), and Tomato spotted wilt virus (TSWV), which were recently reported to infect soybean and azuki bean in Korea. Species-specific primer sets were designed for the detection of each virus, and their specificity and sensitivity were tested using mixed primer sets. From among the designed primer sets, two combinations were selected and further evaluated to estimate the detection limits of uniplex, duplex, and multiplex RT-PCR. The multiplex RT-PCR assay could be a useful tool for the field survey of plant viruses and the rapid detection of ClYVV, PeMoV, and TSWV in leguminous plants.

• Korean Journal of Veterinary Research
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• v.43 no.2
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• pp.231-237
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• 2003

Listeria (L.) monocytogenes in samples could not be detected occasioally by faster growth of other Listeria spp. especially L. innocua. The aim of this study was to develop the differential media and multiplex polymerase chain reaction (PCR) assays for the rapid detection of L. monocytogenes. L. monocytogenes colonies were characterized by their ${\beta}$-hemolysis with fluorescence under 366 nm UV light on the Listeria hemolysis agar (LHA). L. innocua, a species commonly present in foods, did not produce ${\beta}$-hemolysis on LHA. Therefore, one or more colonies of L. monocytogenes were easily distinguished from large populations of L. innocua. The multiplex PCR assays were developed to distinguish from L. monocytogenes and other Listeria spp. with two pairs of primers. The primers were designed in 16S rRNA and listeriolysin O gene for specific amplification of all members of the genus Listeria and L. monocytogenes, respectively. The multiplex PCR assays produced 560 and 938 bp products in L. monocytogenes; only 938 bp products in the genus Listeria. The multiplex PCR assays could detect as little as 50 pg of L monocytogenes DNA. These results indicated that the differential media and multiplex PCR assays might be useful diagnostic tools for the rapid detection of L. monocytogenes.

• Proceedings of the National Institute of Ecology of the Republic of Korea
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• v.1 no.1
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• pp.83-89
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• 2020

Methods for detecting the presence of genetically modified (GM) crops are evolving to comply with legislation and to enhance monitoring by biotechnology companies and regulators. In order to cover a broad range of detection methods for a new GM crop, conventional multiplex PCR methods are required. Based on the genetic information on three GM alfalfa varieties (J101, J163, and KK179), which were recently approved in South Korea, we developed a fast, reliable, and highly specific multiplex polymerase chain reaction (PCR) method with basic PCR equipment and inexpensive reagents. To validate and verify the newly developed multiplex PCR method, we applied a limit of detection assay and random reference material analysis. We also monitored the unintentional environmental release of GM alfalfa in South Korea by performing the multiplex PCR analysis with 91 feral alfalfa specimens collected from 2000 to 2018. Our methodology is a sensitive, simple, quick, and inexpensive tool for detecting and identifying three GM alfalfa varieties.

• Food Science and Biotechnology
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• v.18 no.3
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• pp.694-699
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• 2009

A multiplex polymerase chain reaction (PCR) method was developed for the detection of 4 events of genetically modified (GM) soybean. The event-specific primers were designed from 4 events of GM soybean (RRS, A2704-12, DP356043-5, and MON89788). The lectin was used as an endogenous reference gene of soybean in the PCR detection. The primer pair YjLec-4-F/R producing 100 bp amplicon was used to amplify the lectin gene and no amplified product was observed in any of the 9 different plants used as templates. This multiplex PCR method allowed for the detection of event-specific targets in a genomic DNA mixture of up to 1% GM soybean mixture containing RRS, A2704-12, DP356043-5, and MON89788. In this study, 20 soybean products obtained from commercial food markets were analyzed by the multiplex PCR. As a result, 6 samples contained RRS. These results indicate that this multiplex PCR method could be a useful tool for monitoring GM soybean.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.08a
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• pp.276-276
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• 2013

Here we report an integrated microdevice consisting of an efficient passive mixer, a magnetic separation chamber, and a capillary electrophoretic microchannel in which DNA barcode assay, target pathogen separation, and barcode DNA capillary electrophoretic analysis were performed sequentially within 30 min for multiplex pathogen detection at the single-cell level. The intestine-shaped serpentine 3D micromixer provides a high mixing rate to generate magnetic particle-pathogenic bacteria-DNA barcode labelled AuNP complexes quantitatively. After magnetic separation and purification of those complexes, the barcode DNA strands were released and analyzed by the microfluidic capillary electrophoresis within 5 min. The size of the barcode DNA strand was controlled depending on the target bacteria (Staphylococcus aureus, Escherichia coli O157:H7, and Salmonella typhimurium), and the different elution time of the barcode DNA peak in the electropherogram allows us to recognize the target pathogen with ease in the monoplex as well as in the multiplex analysis. In addition, the quantity of the DNA barcode strand (~104) per AuNP is enough to be observed in the laser-induced confocal fluorescence detector, thereby making single-cell analysis possible. This novel integrated microdevice enables us to perform rapid, sensitive, and multiplex pathogen detection with sample-in-answer-out capability to be applied for biosafety testing, environmental screening, and clinical trials.

• Journal of Plant Biotechnology
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• v.47 no.4
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• pp.309-315
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• 2020

Advances in biotechnology have led to progress in crop genetic engineering to improve agricultural productivity. The use of genetically modified (GM) crops has increased, as have consumers' and regulators' concerns about the safety of GM crops to human health, and ecological biodiversity. As such, the identification of GM crops is a critical issue for developers and distributors, and their labeling is mandatory. Multiplex polymerase chain reaction (PCR) has been developed and its use validated for the detection and identification of GM crops in quarantine. Herein, we established a simultaneous detection method to identify four GM maize events. Event-specific primers were designed between the junction region of transgene and genome of four GM maize lines, namely 5307, DAS-40278-9, MON87460, and MON87427. To verify the efficiency and accuracy of the multiplex PCR we used specificity analysis, limit of detection evaluation, and mixed certified reference materials identification. The multiplex PCR method was applied to analyze 29 living, modified maize volunteers collected in South Korea in 2018 and 2019. We performed multiplex PCR analysis to identify events and confirmed the result by simplex PCR using each event-specific primer. As a result, rather than detecting each event individually, the simultaneous detection PCR method enabled the rapid analysis of 29 GM maize volunteers. Thus, the novel multiplex PCR method is applicable for living modified organism volunteer identification.

• Journal of Microbiology and Biotechnology
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• v.28 no.2
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• pp.210-217
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• 2018

A one-step multiplex reverse transcription PCR (RT-PCR) method comprising six primer sets (for the detection of norovirus GI and GII, hepatitis A virus, rotavirus, and astrovirus) was developed to simultaneously detect four kinds of pathogenic viruses. The size of the PCR products for norovirus GI and GII, hepatitis A virus (VP3/VP1 and P2A regions), rotavirus, and astrovirus were 330, 164, 244, 198, 629, and 449 bp, respectively. The RT-PCR with the six primer sets showed specificity for the pathogenic viruses. The detection limit of the developed multiplex RT-PCR, as evaluated using serially diluted viral RNAs, was comparable to that of one-step single RT-PCR. Moreover, this multiplex RT-PCR was evaluated using food samples such as water, oysters, lettuce, and vegetable product. These food samples were artificially spiked with the four kinds of viruses in diverse combinations, and the spiked viruses in all food samples were detected successfully.

• Food Science and Biotechnology
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• v.17 no.3
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• pp.569-572
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• 2008

A multiplex polymerase chain reaction (PCR) method was developed to simultaneously detect 3 events of genetically modified (GM) maize. The event-specific primers were used to discriminate the following 3 events of GM maize (DAS-59122-7, TC6275, and MIR604) using multiplex PCR method. The zein gene was used as an endogenous maize reference gene in the multiplex PCR detection. The primer pair Zein-FIR producing a 99 bp amplicon was used to amplify the zein gene. The primer JI-Das-F1/R1 for DAS-59122-7, JI-TC6275-F3/R3 for TC6275, and JI-MIR F1/R1 for MIR604 yielded an amplicon of 130, 162, and 197 bp, respectively. The detection limit of multiplex PCR was 1% for DAS-59122-7, TC6275, and MIR604 for one reaction.

• The Plant Pathology Journal
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• v.27 no.4
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• pp.367-371
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• 2011

Multiplex PCR assays were developed for the simultaneous detection of ten important Korean quarantine phytoplasmas. The species-specific primers were designed based on ribosomal protein, putative preprotein translocase Y, immunodominant protein, elongation factor TU, chaperonin protein and the 16S rRNA genes of 'Candidatus (Ca.) Phytoplasma' species. Three main primer sets were prepared from ten designed primer pairs to limit nonspecific amplification as much as possible. The multiplex PCR assay using the three primer sets successfully amplified the correct conserved genes for each 'Ca. Phytoplasma' species. In addition, ten important 'Ca. Phytoplasma' species could be easily determined by recognizing band patterns specific for each phytoplasma species from three primer sets. Moreover, a high sensitivity of multiplex PCR for each primer set was observed for samples containing a low DNA concentration (10 ng/${\mu}l$). This study provides the useful multiplex PCR assay as a convenient method to detect the presence of ten important quarantine phytoplasmas in Korea.