• Journal of Korean Society on Water Environment
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• v.24 no.6
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• pp.817-822
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• 2008

In order to identify various Cryptosporidium species in environment, nested PCR-RFLP and DNA sequencing method were used. The sensitivity of nested PCR-RFLP based on 18s rRNA gene was shown to 1 oocyst. Therefore, we applied nested PCR-RFLP method to environmental samples. As a result, only 4 samples out of 8 samples confirmed as Cryptosporidium parvum by standard method of Cryptosporidium were identified as Cryptosporidium parvum by nested PCR-RFLP and DNA sequencing method. The rest of 4 samples among 8 samples were identified as Cryptosporidium muris, Cryptosporidium bailey. Therefore, in addition to standard method of Cryptosporidium, supplementary verification through nested PCR-RFLP and DNA sequencing should be needed to give more accurate information about risk of Cryptosporidium.

• The Journal of Korean Society of Virology
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• v.27 no.2
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• pp.169-176
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• 1997

In this study, the feasibility of identification and genotypic differentiation of enteroviruses was investigated by using nested reverse transcription-polymerase chain reaction (nested RT-PCR), single-stranded conformation polymorphism (SSCP), and restriction fragment length polymorphism (RFLP) techniques. Two hundred seventy-four clinical samples were assayed by both nested RT-PCR and tube culture method using MRC-5 and MK cells; 58 (86.6%) out of 67 enterovirus culture-positive samples contained enteroviral RNA. In addition, 114 (55.1%) of 207 samples from patients with suspected enteroviral CNS disease with negative viral cultures were positive by the nested RT-PCR. The nested RT-PCR products were genotyped by the SSCP method and the results were compared with serotypes. We could differentiate 6 subtypes, 3 of which are similar to coxsackievirus B3, B5, echovirus 11, plus 3 other subtypes. RFLP cleaved with Sty I, Bgl I, and Xmn I yielded characteristic patterns for each laboratory strains. This study demonstrates the usefulness of the RT-PCR for the rapid diagnosis of enterovirus infection and the potentials of the SSCP method for differentiation of enterovirus strains.

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.9
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• pp.1237-1243
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• 2002

We have developed a reliable and noninvasive method for swine genotyping of single locus nuclear gene with aged single hair follicles delivered by general mail. The method is based on booster and nested PCR amplification with step-wise increase of primers and dNTPs concentrations followed by restriction endonuclease digestion. To establish this method, the ryanodine receptor (RYR 1) locus which is an economically important trait in swine industry was employed for genotyping experiment. The 3-step PCR amplication method is much less dependent on the quantity and quality of template DNA and produces enough amplification product for the detection on the ethidium bromide-stained gel such as RFLP analysis. A total of 120 pigs were subjected to the RYR 1 genotyping analysis using three-step PCR method which amplified enough quantity of PCR products from the aged single hair follicles for RFLP analysis and genotyping results were identical to the results of the corresponding ethanol-fixed skeletal muscle tissue. This approach will be a great help for porcine breeders and investigators in genotyping of swine. They can receive genotyping results later by simply plucking single hairs of their pigs at farm and sending them in general mail to the diagnostic laboratory which eliminates the inconveniences to collect ear tissue or blood cells from pigs, or the investigator's need for travel to farms in order to collect fresh hair samples.

• Korean Journal of Head & Neck Oncology
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• v.12 no.2
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• pp.169-176
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• 1996

Tuberculous cervical lymphadenitis is still an important cause of neck mass in Korea. Tuberculosis is an important differential diagnosis in patients of cervical lymphadenopathy. Rapid and sensitive test for the diagnosis of tuberculosis is essential for the approapiate treatment. Up to now, conventional diagnostic methods for M. tuberculosis were acid-fast bacilli(AFB) stain and culture of M. tuberculosis. The direct microscopic examination of AFB by Ziehl-Neelsen stain is rapid, but often negative. The culture for M. tuberculosis is time-consuming, taking 4 to 8 weeks. Recently various methods to detect Mycobacterial DNA, including PCR and restriction fragment length polymorphism(RFLP) analysis have been reported. Here we represent a simple method for the confirmation of M. tuberculosis and exclusion of the other Mycobacterial species by RFLP analysis and silver staining of polyacrylamide gel electrophoresis after nested PCR for a repetitive DNA sequence(IS986) specific for M. tuberculosis from fresh or paraffin-embedded biopsy specimens. This result leads us to conclude that this method is simple, rapid and possibly applicable to confirm M. tuberculosis and rule out the other Mycobacteria species from the clinical specimens in the clinical laboratories.

• Journal of Microbiology
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• v.44 no.1
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• pp.42-49
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• 2006

In this study, we describe our newly-developed sensitive two-stage PCR procedure for the detection of 13 common mycoplasmal contaminants (M. arthritidis, M. bovis, M. fermentans, M. genitalium, M. hominis, M. hyorhinis, M. neurolyticum, M. orale, M. pirum, M. pneumoniae, M. pulmonis, M. salivarium, U. urealyticum). For primary amplification, the DNA regions encompassing the 16S and 23S rRNA genes of 13 species were targeted using general mycoplasma primers. The primary PCR products were then subjected to secondary nested PCR, using two different primer pair sets, designed via the multiple alignment of nucleotide sequences obtained from the 13 mycoplasmal species. The nested PCR, which generated DNA fragments of 165-353 bp, was found to be able to detect 1-2 copies of the target DNA, and evidenced no cross-reactivity with the generated DNA of related microorganisms or of human cell lines, thereby confirming the sensitivity and specificity of the primers used. The identification of contaminated species was' achieved via the performance of restriction fragment length polymorphism (RFLP) coupled with Sau3AI digestion. The results obtained in this study furnish evidence suggesting that the employed assay system constitutes an effective tool for the disagnosis of mycoplasmal contamination in cell culture systems.

• Korean Journal of Clinical Laboratory Science
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• v.47 no.2
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• pp.83-89
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• 2015

Although Mycobacterium tuberculosis complex strains remain responsible for the majority of diseases caused by mycobacterial infections worldwide, the increase in HIV (human immuno deficiency virus) infections has allowed for the emergence of other non-tuberculous mycobacteria as clinically significant pathogens. M. tuberculosis was detected by two-tube nested polymerase chain reaction (PCR) and non-tuberculous mycobacteria was detected by PCR-restriction fragment length polymorphism (RFLP) with Msp I. Result of niacin test is equal to result of two-tube nested PCR after culture for M. tuberculosis. In this study, acid fast bacilli stain (AFB. stain) >2+ case, Detection of Mycobacteria is similar to result before culture and after culture. AFB. stain <1+ case, result of mycobacteria is distinguished. Conclusionly, these results suggest that identification of mycobacteria must go side by side both culture and PCR for more fast and accuracy.

• Toxicological Research
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• v.32 no.1
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• pp.81-87
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• 2016

Aflatoxin B1 (AFB1) is produced by Aspergillus flavus growing in feedstuffs. Early detection of maize contamination by aflatoxigenic fungi is advantageous since aflatoxins exert adverse health effects. In this study, we report the development of an optimized conventional PCR for AFB1 detection and a rapid, sensitive and simple screening Real-time PCR (qPCR) with SYBR Green and two pairs of primers targeting the aflR genes which involved aflatoxin biosynthesis. AFB1 contaminated maize samples were divided into three groups by the toxin concentration. Genomic DNA was extracted from those samples. The target genes for A. flavus were tested by conventional PCR and the PCR products were analyzed by electrophoresis. A conventional PCR was carried out as nested PCR to verify the gene amplicon sizes. PCR-RFLP patterns, obtained with Hinc II and Pvu II enzyme analysis showed the differences to distinguish aflatoxin-producing fungi. However, they are not quantitative and need a separation of the products on gel and their visualization under UV light. On the other hand, qPCR facilitates the monitoring of the reaction as it progresses. It does not require post-PCR handling, which reduces the risk of cross-contamination and handling errors. It results in a much faster throughout. We found that the optimal primer annealing temperature was $65^{\circ}C$. The optimized template and primer concentration were $1.5{\mu}L\;(50ng/{\mu}L)$ and $3{\mu}L\;(10{\mu}M/{\mu}L)$ respectively. SYBR Green qPCR of four genes demonstrated amplification curves and melting peaks for tub1, afIM, afIR, and afID genes are at $88.0^{\circ}C$, $87.5^{\circ}C$, $83.5^{\circ}C$, and $89.5^{\circ}C$ respectively. Consequently, it was found that the four primers had elevated annealing temperatures, nevertheless it is desirable since it enhances the DNA binding specificity of the dye. New qPCR protocol could be employed for the determination of aflatoxin content in feedstuff samples.

• The Plant Pathology Journal
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• v.39 no.1
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• pp.149-157
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• 2023

Phytoplasmas were discovered in diseased Elaeocarpus sylvestris trees growing on Jeju Island that showed symptoms of yellowing and darkening in the leaves. Leaf samples from 14 symptomatic plants in Jeju-si and Seogwipo-si were collected and phytoplasma 16S rRNA was successfully amplified by nested polymerase chain reaction using universal primers. The sequence analysis detected two phytoplasmas, which showed 99.5% identity to 'Candidatus Phytoplasma asteris' and 'Ca. P. malaysianum' affiliated to 16SrI and 16SrXXXII groups, respectively. Through polymerase chain reaction-restriction fragment length polymorphism (RFLP) analyses using the AfaI (RsaI) restriction enzyme, the presence of two phytoplasmas strains as well as cases of mixed infection of these strains was detected. In a virtual RFLP analysis with 17 restriction enzymes, the 16S rRNA sequence of the 'Ca. P. asteris' strain was found to match the pattern of the 16SrI-B subgroup. In addition, the phytoplasmas in the mixed-infection cases could be distinguished using specific primer sets. In conclusion, this study confirmed mixed infection of two phytoplasmas in one E. sylvestris plant, and also the presence of two phytoplasmas (of the 16SrI and 16SrXXXII groups) in Jeju Island (Republic of Korea).

• Clinical and Experimental Reproductive Medicine
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• v.32 no.4
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• pp.293-300
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• 2005

연구목적: 단일 유전자 이상에 대한 착상전 유전진단을 성공적으로 시행하기 위해서는 효과적이고 신뢰도가 높은 PCR 방법의 확립이 중요하다. 본 연구에서는 alkaline lysis와 duplex nested PCR 방법을 단일 림프구와 할구의 유전자 분석에 적용하여 그 효용성을 확인하고자 하였다. 재료 및 방법: 단일 유전자의 이상이 확인된 Duchenne muscular dystrophy (DMD), ornithine transcarbamylase (OTC) 결핍증과 epidermolysis bullosa (EB) 가계의 대상자들에서 채취한 단일 림프구와 공여 받은 배아의 할구를 이용하여 각각 PCR, restriction fragment length polymorphism (RFLP)와 direct DNA sequencing 분석을 시행하였다. 이러한 분석에서 유전자 증폭률 (amplification rate)과 두개의 allele 중에서 하나의 allele이 증폭되지 않는 allele drop-out (ADO) 빈도에 대해 살펴보았다. 결 과: 단일 림프구와 할구를 이용한 PCR 방법의 유전자 증폭률은 DMD에서 91.1%와 81.8%, OTC 결핍증에서 96.0%와 78.1%, EB에서 91.3%와 90.0%를 각각 나타냈으며, ADO 빈도는 OTC 결핍증에서 13.3%, EB에서 16.8%로 관찰되었다. 결 론: 본 연구에서 적용한 alkaline lysis와 duplex nested PCR 방법은 단일 유전자에 대한 착상전 유전진단에 성공적으로 적용할 수 있는 방법으로 생각되며, ADO 빈도를 최소화할 수 있는 효율적인 방법의 개발에 대한 지속적인 연구가 필요하다.

• Parasites, Hosts and Diseases
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• v.54 no.4
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• pp.423-429
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• 2016

Cryptosporidium is an important pathogen causing gastrointestinal disease in snakes and is distributed worldwide. The main objectives of this study were to detect and identify Cryptosporidium species in captive snakes from exotic pet shops and snake farms in Thailand. In total, 165 fecal samples were examined from 8 snake species, boa constrictor (Boa constrictor constrictor), corn snake (Elaphe guttata), ball python (Python regius), milk snake (Lampropeltis triangulum), king snake (Lampropeltis getula), rock python (Python sebae), rainbow boa (Epicrates cenchria), and carpet python (Morelia spilota). Cryptosporidium oocysts were examined using the dimethyl sulfoxide (DMSO)-modified acid-fast staining and a molecular method based on nested-PCR, PCR-RFLP analysis, and sequencing amplification of the SSU rRNA gene. DMSO-modified acid-fast staining revealed the presence of Cryptosporidium oocysts in 12 out of 165 (7.3%) samples, whereas PCR produced positive results in 40 (24.2%) samples. Molecular characterization indicated the presence of Cryptosporidium parvum (mouse genotype) as the most common species in 24 samples (60%) from 5 species of snake followed by Cryptosporidium serpentis in 9 samples (22.5%) from 2 species of snake and Cryptosporidium muris in 3 samples (7.5%) from P. regius.