• International Journal of Oral Biology
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• 제46권3호
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• pp.140-145
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• 2021

This study aimed to develop Lautropia mirabilis-specific quantitative real-time polymerase chain reaction (qPCR) primers based on the sequence of DNA-directed RNA polymerase subunit beta gene. The PrimerSelect program was used in designing of the qPCR primers, RTLam-F4 and RTLam-R3. The specificity of the qPCR primers were performed by conventional PCR with 37 strains of 37 oral bacterial species, including L. mirabilis. The sensitivity of the primers was determined by qPCR with the serial dilution of purified genomic DNA of L. mirabilis KCOM 3484, ranged from 4 ng to 4 fg. The data showed that the qPCR primers could detect only L. mirabilis strains and as little as 40 fg of genome DNA of L. mirabilis KCOM 3484. These results indicate that this qPCR primer pair (RTLam-F4/RTLam-R3) may be useful for species-specific detection of L. mirabilis in epidemiological studies of oral bacterial infectious diseases such as periodontal disease.

• Environmental Engineering Research
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• 제20권1호
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• pp.51-57
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• 2015

As expected, the expression of denitrifying genes in a Typha wetland (relatively stagnant compared to other ponds), showing higher nitrogen removal efficiency in summer, was affected by temperature. The abundance and gene transcripts of nitrate reductase (narG), nitrite reductase (nirS), nitric oxide reductase (norB), and nitrous oxide reductase (nosZ) genes in seasonal sediment samples taken from the Acorus and Typha ponds of free surface flow constructed wetlands were investigated using quantitative polymerase chain reaction (Q-PCR) and quantitative reverse transcription PCR (Q-RT-PCR). Denitrifying gene copy numbers ($10^5-10^8$ genes $g^{-1}$ sediment) were found to be higher than transcript numbers-($10^3-10^7$ transcripts $g^{-1}$ sediment) of the Acorus and Typha ponds, in both seasons. Transcript numbers of the four functional genes were significantly higher for Typha sediments, in the warm than in the cold season, potentially indicating greater bacterial activity, during the relatively warm season than the cold season. In contrast, copy numbers and expression of denitrifying genes of Acorus did not provide a strong correlation between the different seasons.

• International Journal of Oral Biology
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• 제44권3호
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• pp.96-100
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• 2019

The purpose of this study was to develop Peptoniphilus mikwangii-specific quantitative real-time polymerase chain reaction (qPCR) primers based on the 16S ribosomal RNA (16S rDNA) gene. The specificity of the primers was determined by conventional PCR using 29 strains of 27 oral bacterial species including P. mikwangii. The sensitivity of the primers was determined by qPCR using the purified genomic DNA of P. mikwangii KCOM $1628^T$ (40 ng to 4 fg). The data showed that the qPCR primers (RTB134-F4/RTB134-R4) could detect P. mikwangii strains exclusively and as little as 40 fg of the genomic DNA of P. mikwangii KCOM $1628^T$. These results suggest that the developed qPCR primer pair can be useful for detecting P. mikwangii in epidemiological studies of oral bacterial infectious diseases.

• International Journal of Oral Biology
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• 제41권3호
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• pp.149-154
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• 2016

The purpose of this study was to develop Streptococcus sobrinus-specific qPCR primers based on the nucleotide sequence of the RNA polymerase ${\beta}-subunit$ gene (rpoB). The specificity of the primers was determined by conventional polymerase chain reaction (PCR) with 12 strains of S. sobrinus and 50 strains (50 species) of non-S. sobrinus bacteria. The sensitivity of the primers was determined by quantitative real-time PCR (qPCR) with serial dilutions of the purified genomic DNAs (40 ng to 4 fg) of S. sobrinus ATCC $33478^T$. The specificity data showed that the S. sobrinus-specific qPCR primers (RTSsob-F4/RTSsob-R4) detected only the genomic DNAs of S. sobrinus strains with a detection limit of up to 4 fg of S. sobrinus genomic DNA. Our results suggest that the RTSsob-F4/RTSsob-R4 primers are useful in detecting S. sobrinus with high sensitivity and specificity for epidemiological studies of dental caries..

• 한국진공학회:학술대회논문집
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• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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• pp.375.1-375.1
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• 2016

Polymerase chain reaction (PCR) has revolutionized genetics and become one of the most popular techniques in modern biological and medical sciences. It can be used not only as an in vitro DNA amplification method but also used in many bioassay applications. The PCR can be used to exponentially produce a large number of DNA copies from a small quantity of DNA molecules in a few hours. However, as unwanted DNA fragments are also often manufactured, the amplification efficiency of PCR is decreased. To overcome this limitation, several nanomaterials have been employed to increase the specificity of the PCR reaction. Recently, graphene has attracted a great interest for its excellent electron transfer, thermal and biocompatibility. Especially, gold nanoparticle-coated graphene oxide (GO/AuNPs) led to enhance electron and thermal transfer rate and low-charge transfer resistance. Therefore, we report the development of a demonstration for the PCR efficiency using a large-scale production of the GO and combination of gold nanoparticles. Because a thermal conductivity is an important factor for improving the PCR efficiency in different DNA polymerases and different size samples. When PCR use GO/AuNPs, the result of transmission electron microscopy and real-time quantitative PCR (qPCR) showed an enhanced PCR efficiency. We have demonstrated that GO/AuNPs would be simply outperformed for enhancing the specificity and efficiency of DNA amplification procedure.

• 한국수정란이식학회지
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• 제25권2호
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• pp.111-116
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• 2010

Sperm chromatin integrity is essential for successful fertilization and development of an embryo. Reported here is a quantification of DNA fragments which is intimately associated with reproductive potential to provide one of criteria for sperm chromatin integrity. Three sperm populations were considered: CONTROL (no treatment), UV irradiation (48mW/$cm^2$, 1h) and $H_2O_2$ (oxidative stress induced by hydrogen peroxide, 10 mM, 50 mM and 100 mM). DNA fragments in boar sperm were evaluated by using ligation-mediated quantitative real-time polymerase chain reaction (LM-qPCR) assay, which relies on real-time qPCR to provide a measure of blunt 5' phosphorylated double strand breaks in genomic DNA. The results in agarose gel electrophoresis showed no significant DNA fragmentation and no dose-dependent response to $H_2O_2$. However, the remarkable difference in shape and position was observed in melting curve of LM-qPCR. This result supported that the melting curve analysis of LM-qPCR presented here, could be more sensitive and accurate than previous DNA fragmentation assay method.

• 농업과학연구
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• 제49권4호
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• pp.795-807
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• 2022

The development and commercialization of industrial genetically modified (GM) organisms is actively progressing worldwide, highlighting an increased need for improved safety management protocols. We sought to establish an environmental monitoring method, using real-time polymerase chain reaction (PCR) and propidium monoazide (PMA) treatment to develop a quantitative detection protocol for living GM microorganisms. We developed a duplex TaqMan quantitative PCR (qPCR) assay to simultaneously detect the selectable antibiotic gene, ampicillin (AmpR), and the single-copy Escherichia coli taxon-specific gene, D-1-deoxyxylulose 5-phosphate synthase (dxs), using a direct cell suspension culture. We identified viable engineered E. coli cells by performing qPCR on PMA-treated cells. The theoretical cell density (true copy numbers) calculated from mean quantification cycle (Cq) values of PMA-qPCR showed a bias of 7.71% from the colony-forming unit (CFU), which was within ±25% of the acceptance criteria of the European Network of GMO Laboratories (ENGL). PMA-qPCR to detect AmpR and dxs was highly sensitive and was able to detect target genes from a 10,000-fold (10^-4) diluted cell suspension, with a limit of detection at 95% confidence (LOD_95%) of 134 viable E. coli cells. Compared to DNA-based qPCR methods, the cell suspension direct PMA-qPCR analysis provides reliable results and is a quick and accurate method to monitor living GM E. coli cells that can potentially be released into the environment.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• 제15권1호
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• pp.38-43
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• 2012

Purpose: Epstein-Barr virus (EBV) hepatitis is a usually asymptomatic and self-limiting disease in immunocompetent patients. However, the range of severity is wide, and the serological diagnosis is typically difficult until the convalescent phase. Thus, we examined the value of plasma EBV DNA real-time quantitative polymerase chain reaction (RT-qPCR) in EBV hepatitis for the timely diagnosis and the relationship between EBV viral load and clinical severity. Methods: Sixty samples were confirmed as having EBV infection by RT-qPCR with the EBV BALF5 gene sequence. We examined the clinical characteristics of EBV hepatitis by reviewing medical records. Results: The median total duration of fever was 8 days (range: 0-13 days). The mean peak value of aspartate aminotransferase (AST) was $241{\pm}214$ U/L, and the mean peak value of alanine aminotransferase (ALT) was $298{\pm}312$ U/L. There was no correlation between the serum levels of liver enzyme and plasma EBV DNA titer ($p$=0.1) or between median total duration of fever and EBV DNA titer ($p$=0.056). The median age of the EBV VCA IgM-negative group was lower compared with the EBV VCA IgM-positive group in EBV hepatitis (2 years vs. 6 years, $p$=0.0009). Conclusion: The severity of EBV hepatitis does not correlate with circulating EBV DNA load according to our data. Furthermore, we suggest that plasma EBV PCR may be valuable in young infants in whom the results of serology test for EBV infection commonly are negative.

• 공업화학
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• 제33권3호
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• pp.235-241
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• 2022

유엔이 발표한 세계 물개발 보고서는 2030년까지 식수가 현재보다 40% 감소할 것으로 전망하고 있다. 이는 물의 양이 감소하는 것이 아니라, 환경오염으로 인해 상수원이 오염되는 것을 말한다. 미생물이 수질에 깊은 연관이 있기 때문에 미생물의 분석은 수질관리에 매우 중요하다. 현재 미생물 분석에 사용되는 방법은 배양 후 현미경을 통한 모양과 형태를 분석하는 것이 가장 일반적이나, 유전자분석 기술이 발달함에 따라 현미경을 통한 미생물 분석 방식에 qPCR(quantitative polymerase chain reaction) 적용이 가능해졌고 활용방법 등이 연구되었다. 그 중에는 역전사 단계를 추가하여 RNA 분석에 용이성을 부여한 RT-qPCR법과 미생물 배양분석에 접목시켜 검사시간을 단축시키는 ICC-qPCR, 자연에서 채취한 샘플의 위양성율을 감소시키는 데 용이한 viability qPCR, 다중분석에 용이한 multiplex qPCR, 소량의 샘플만으로 분석이 가능한 microfluidic qPCR법 등이 있다. 본 논문에서는 이처럼 qPCR 방법이 미생물 분석에 적용되는 사례와 방식의 원리, 그리고 발전 방향에 대해 소개하고자 한다.

• 대한소아치과학회지
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• 제45권1호
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• pp.32-40
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• 2018

본 연구는 치태의 성숙도에 따라 치태를 서로 다른 색상으로 염색하는 GC Tri Plaque ID $Gel^{TM}$(GC corporation, Tokyo, Japan)을 이용하여 치아 우식 위험도를 평가하고자 하였다. 치아 우식의 발생 및 진행과 연관된 균인 Streptococcus mutans, Streptococcus sobrinus, Lactobacillus spp.의 수를 Quantitative real-time polymerase chain reaction (qRT-PCR)로 측정하여 치아 우식 위험도를 보았다. 본 실험은 강릉원주대학교 치과병원 임상시험 심사위원회의 심의를 받고 진행하였다. 강릉원주대학교 치과병원 소아치과에 내원한 전신질환이 없는 건강한 9 - 12세의 초등학생 15명의 치면을 착색제로 염색하였다. 치태의 성숙도에 따라 서로 다른 세가지 색상으로 염색되었으며 색상별로 3개의 실험군인 I군(pink/red), II군(blue/purple), III군(light blue)으로 나누었다. 3개의 실험군에서 각각 DNA를 추출한 후, qRT-PCR을 이용하여 S. mutans, S. sobrinus, Lactobacillus spp.의 수를 측정하였다. 3개의 실험군 사이에 S. mutans, S. sobrinus와 Lactobacillus spp. 균 수의 유의한 차이가 관찰되었으며 3종류의 균 모두 III군에서 가장 많이 관찰되었다(p < 0.05). GC Tri Plaque ID $Gel^{TM}$는 기존 착색제와는 달리 치태의 성숙도에 따라 서로 다른 세가지 색상으로 염색되며, 치태 염색 색상의 차이는 치아 우식 관련 균 수의 차이를 보여주었다. GC Tri Plaque ID $Gel^{TM}$이 치아 우식 위험도를 평가하는 하나의 지표로서 사용될 수 있는 가능성을 확인하였다.