• Food Science and Biotechnology
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• v.17 no.6
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• pp.1171-1177
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• 2008

This study was undertaken to classify Enterobacter sakazakii isolates from 13 powdered infant formula products, 25 powdered weaning diet products, and 33 weaning diet ingredients on polymerse chain reaction (PCR) methods. The numbers of the isolates from 1 powdered infant formula product, 7 powdered weaning diet products, and 6 weaning diet ingredients were 1, 14, and 8, respectively. The contaminated ingredients were 1 rice powder, 2 millet powders, 2 vegetable powders, and 1 fruit and vegetable premix. PCR with the primer of repetitive extragenic palindromic element (REP-PCR) and random amplification of polymorphic DNA(RAPD) were effective in discriminating among the isolates, but tRNA-PCR and PCR with the primer of l6S-23S internal transcribed spacer (ITS-PCR) were not. Some of E. sakazakii isolates from vegetable powders, fruit and vegetable premix, and millets powders were classified into the clonal groups based on the DNA patterns in the REP-PCR and RAPD analysis. A close genetic relationship among the isolates from some of the powdered weaning diet products and the rice powder was also detected in the cluster analysis based on the DNA patterns in RAPD.

• Food Science of Animal Resources
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• v.29 no.5
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• pp.647-652
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• 2009

A duplex PCR technique was applied for specific identification of cow and goat milk in milk products by using primers targeting the mitochondrial 12S rRNA gene. Duplex PCR using primers specific for cow and goat generated specific fragments of 223bp and 326bp from cow and goat milk DNA, respectively. Duplex PCR was applied to 15 milk products purchased from the market to verify label statements. The labeling statements of four market milk products, three yoghurt products, and one whole milk powder product were confirmed in the duplex PCR. The labeling statements of five of seven infant milk powder products were also confirmed by duplex PCR but the other two products were shown to be contaminated with either cow or goat milk. The proposed duplex PCR provides a rapid and sensitive approach to detection of as little as 0.1% cow milk in goat milk and one-step detection of cow or goat milk in milk products.

• The Plant Pathology Journal
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• v.31 no.1
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• pp.25-32
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• 2015

Pseudomonas coronafaciens causes halo blight on oats and is a plant quarantine bacterium in many countries, including the Republic of Korea. Using of the certificated seed is important for control of the disease. Since effective detection method of P. coronafaciens is not available yet, PCR and TaqMan PCR assays for specific detection of P. coronafaciens were developed in this study. PCR primers were designed from the draft genome sequence of P. coronafaciens LMG 5060 which was obtained by the next-generation sequencing in this study. The PCR primer set Pc-12-F/Pc-12-R specifically amplified 498 bp from the 13 strains of P. coronafaciens isolated in the seven different countries (Canada, Japan, United Kingdom, Zimbabwe, Kenya, Germany, and New Zealand) and the nested primer set Pc-12-ne-F/Pc-12-ne-R specifically amplified 298 bp from those strains. The target-size PCR product was not amplified from the non-target bacteria with the PCR and nested primer sets. TaqMan PCR with Pc-12-ne-F/Pc-12-ne-R and a TaqMan probe, Pc-taqman, which were designed inside of the nested PCR amplicon, generated Ct values which in a dose-dependent manner to the amount of the target DNA and the Ct values of all the P. coronafaciens strains were above the threshold Ct value for positive detection. The TaqMan PCR generated positive Ct values from the seed extracts of the artificially inoculated oat seeds above 10 cfu/ml inoculation level. PCR and TaqMan PCR assays developed in this study will be useful tools to detect and identify the plant quarantine pathogen, P. coronafaciens.

• Research in Plant Disease
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• v.11 no.1
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• pp.48-55
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• 2005

Cylindrocarpon destructans is a soil-borne plant pathogenic fungus causing root rot on ginseng and trees. Rapid and exact detection of this pathogen was practiced on ginseng seedlings by nested PCR using speciesspecific primer set. The second round of PCR amplification by Dest 1 and Dest 4 primer set formed 400 bp of species-specific fragment of C. destructans from the product of first round of amplification by ITS 1 and ITS 4 primer set. In the PCR sensitivity test based on DNA density, nested PCR detected to the limit of one fg and it meant the nested PCR could detect up to a few spores of C. destructans. Also, nested PCR made it possible to detect the pathogen from ginseng seedlings infected by replantation on artificial infested soil. Our nested PCR results using species-specific primer set could be utilized for diagnosis of root rot disease in ginseng cultivation.

• Microbiology and Biotechnology Letters
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• v.45 no.4
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• pp.358-364
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• 2017

Asymmetric PCR preferentially amplifies one DNA strand for use in DNA hybridization studies. Linear-After-The-Exponential-PCR (LATE-PCR) is an advanced asymmetric PCR method which uses innovatively designed primers at different concentrations. This study aimed to optimise LATE-PCR parameters to produce single-stranded DNA of Candida spp. and Aspergillus spp. for detection via probe hybridisation. The internal transcribed spacer (ITS) region was used to design limiting primer and excess primer for LATE-PCR. Primer annealing and melting temperature, difference of melting temperature between limiting and excess primer and concentration of primers were optimized. In order to confirm the presence of single-stranded DNA, the LATE-PCR product was hybridised with digoxigenin labeled complementary oligonucleotide probe specific for each fungal genus and detected using anti-digoxigenin antibody by dot blotting. Important parameters that determine the production of single-stranded DNA in a LATE-PCR reaction are difference of melting temperature between the limiting and excess primer of at least $5^{\circ}C$ and primer concentration ratio of excess primer to limiting primer at 20:1. LATE-PCR products of Candida albicans, Candida parapsilosis, Candida tropicalis and Aspergillus terreus at up to 1:100 dilution and after 1 h hybridization time, successfully hybridised to respective oligonucleotide probes with no cross reactivity observed between each fungal genus probe and non-target products. For Aspergillus fumigatus, LATE-PCR products were detected at 1:10 dilution and after overnight hybridisation. These results indicate high detection sensitivity for single-stranded DNA produced by LATE-PCR. In conclusion, this advancement of PCR may be utilised to detect fungal pathogens which can aid the diagnosis of invasive fungal disease.

• Korean Journal of Microbiology
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• v.43 no.3
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• pp.179-185
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• 2007

In this study, we used the method of guanidin isothiocyanate and boiling with Chelex-100 resin to extract genomic DNA of Ralstonia solanacearum from soil. It is more efficient than general protocols to remove inhibitory compounds in soil and R. solanacearum on. Then, we applied polymerase chain reaction and DNA enzyme-linked immunosorbent assay (ELISA) to identify and detect pathogen. The fliC gene of R. solanacearum was selected for specific detection of pathogen and primer sets were designed. Among the primer sets, two specific and sensitive primer sets, RsolfliC(forward: 5-GAACGCCAACGGTGCGAACT-3 and reverse; 5-GGCGGCCTTCAGGGAGGTC-3, designed by J. $Sch\ddot{o}nfeld$ et al.) and RS_247 (forward: 5-GGCGGTCTGTCGGCRG-3 and reverse; 5-CGGTCGCGTTGGCAAC-3 designed by this study), were designed to perform nested PCR. Nested PCR primer was labeled with biotin for hybridization between nested PCR product and probe to analyze with DNA ELISA.

• Journal of Applied Biological Chemistry
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• v.49 no.4
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• pp.143-147
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• 2006

A rapid PCR-based assay for detecting hepatitis B viral DNA(HBV DNA) in serum and plasma was developed using a new PCR instrument named GenSpector(TMC-1000, Samsung electronics). PCR was carried out using a chip-based platform, which enabled 50 PCR cycles with internal controls, and melting-curve analysis in 30 minutes. Verification of the amplified HBV DNA product and the internal control was based on specific melting temperatures(Tm) analysis, executed by the GenSpector software. Primers were designed within the region conserved through HBV genotypes A to F. The lower limit of detection was 840 copies/ml serum, conducted with serial dilutions of a HBV DNA positive control(ACCURUN 325 series 700, Boston Biomedica Inc.). The assay was also compared to another assay for HBV DNA(Versant HBV DNA 3.0 assay, Bayer HealthCare) for 200 samples(each 100 clinical negative and positive samples). The sensitivity and specificity were 100% matched. This rapid PCR-based assay is specific, reproducible, and enables qualitative detection of HBV DNA.

• Journal of Mushroom
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• v.2 no.3
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• pp.145-148
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• 2004

This study was carried out to screen the fruiting body formation-specific genes from the medicinal mushroom Cordyceps militaris. A cDNA synthesized using total RNA from 4 stages of mushroom development, mycelium, primordium, immature fruiting body and mature fruiting body. Differential expression gene screening was performed by DD-PCR(Differential Display Arbitrary Primer PCR) with cDNA, we sequenced partial 6 genes using pGEM cloning vector. The DNA Sequence of the six DD-PCR products derived from differentially expressed genes was compared to that in the GenBank database by using the NCBI BLAST search to identify similarities to known sequences. Sequence analysis showed that six of DD-PCR products have unknown sequence.

• The Journal of the Korean Society for Microbiology
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• v.35 no.4
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• pp.283-288
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• 2000

The PCR primer set JW21-JW22 of Weiss et al. (19), which was reported to amplify a 139-bp fragment of the l6S rRNA gene of Helicobacter pylori, has been recently used for the detection of H. pylori in clinical specimens. However, when we applied JW21-JW22 PCR to other members of the genus Helicobacter and unrelated microorganisms, all of these bacteria produced a 139-bp PCR product. Therefore, we designed a novel primer set, HPU185-HPL826, which produced a 642-bp amplicon of the l6S rRNA gene of H. pylori. Then we further examined the specificity of the novel PCR assay using Southern blot hybridization with an internal probe, HPP225. The PCR assay described in this study was shown to be highly sensitive and specific only to the H. pylori 16S rRNA gene sequences.

• Korean Journal of Veterinary Research
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• v.45 no.3
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• pp.335-339
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• 2005

The melanocortin 1 receptor (MC1R) plays an important role in regulation of melanin pigment synthesis within mammalian melanocytes. Mutations within the gene encoding MC1R have been shown to explain coat color variations within several mammalian species including cattle. To develope a rapid and accurate method for the identification of Hanwoo, we performed a modified PCR-RFLP analysis of MC1R gene using single nucleotide polymorphism (SNP) within MC1R as a target. A size of 538 bp (537 bp for Hanwoo) was amplified by PCR, digested with Hpa II, and electrophoresed on a 1.5% agarose gel. A PCR product from Hanwoo showed a single band of 537 bp, whereas two fragments of 328 bp and 210 bp were detected in both Holstein and Black angus. The current result suggests that the PCR-RFLP using our primers and enzyme digestion system would be very accurate, easy and reproducible method to discriminate between Hanwoo and Holstein/Black angus meat.