• Parasites, Hosts and Diseases
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• 제35권3호
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• pp.203-210
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• 1997

이질아메바 병원성 분리주에서 특이적으로 발현되는 mRNA를 동정하고자 differential display reverse transcription-polymerase chain reaction(DDRT-PCR)을 수행하여 병원성 특이 증폭산물을 확인하였다. 한국인에서 검출한 이질아메바 병원성 분리주 YS-27과 Entamoeba dispar분리주인 S 16으로부터 정제한 mRAN를 주형으로 11개의 arbitrary primer와 3개의 one base anchored $oligo-dT_{11}M$(M: A, C 또는 G)의 조합을 이용, DDRT-PCR을 실시한 결과 31개의 분획이 YS-27주에서만 증폭된 것으로 확인되었다. 이 331개 DNA 중 21개는 cysteine proteinase 유전자와 상동성을 나타내었다. YS-27주로부터 제작된 cDNA library를 나머지 DNA를 탐침으로 사용, 검색하여 최종 4개의 clone을 얻었다. 이 4개의 clone을 이용, immunoscreening을 수행한 결과, 이 clone들은 이질아메바 감염자 혈청과 양성반응을 나타내고 있었다.

• 한국식품과학회지
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• 제35권3호
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• pp.470-474
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• 2003

식중독은 세균에 의한 발병이 대부분이다. 따라서 식품에서 식중독 원인균을 신속하게 탐색하게 식중독으로부터의 되면 피해를 줄일 수 있을 것이다. 고전적인 식중독 원인균 탐색은 증균, 선택적 배지를 이용한 isolation, 생화학적 특징을 활용하는 분석이 있으나 많은 시간이 소요되는 단점을 갖고 있었다. 본 연구는 16S rRNA gene(16S rDNA)로부터 얻은 DNA 염기 서열을 이용 식중독 원인균의 특이적 oligonucleotide probe을 제작 reverse dot blot hybridization과 PCR 방법을 이용하여 고전적인 방법보다 빠른 시간 내에 식품에서 원인균을 탐색 할 수 있었다. 우유를 인공적으로 본 연구에서 사용한 균주로 오염시킨 후 DNA를 추출하여 PCR 증폭산물과 oligonucleotide probe를 hybridization 시킨 결과 oligonucleotide probe를 hybridization 시킨 결과 oligonucleotide probe가 위치한 곳에서 발색 반응이 나타났다. 본 연구에서 본 연구를 통해 DNA microchip으로 활용 짧은 시간 내에 많은 종류의 식중독 원인균을 탐색 할 수 있는 가능성을 확인하였다.

• 한국염색가공학회지
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• 제8권4호
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• pp.25-30
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• 1996

This study was carried out to examine the effect of lipase on the removal of tripalmitin in the various conditions of washing. The relations between the removal and the hydrolysis of tripalmitin by lipase were discussed. The hydrolysis characteristics of lipase were examined by a colorimetric determination of liberated fatty acids as a new assay of lipase in reverse micelies. The hydrolysis of tripalmitin by lipase was increased with the increase of reaction time and reaction above lipase concentration 150mg/l pH at reaction temperature 4$0^{\circ}C$.

• Animal cells and systems
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• 제5권1호
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• pp.65-69
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• 2001

Obtaining mutant animals is important for studying the function of a particular gene. A chemical mutagenesis was first carried out to generate mutations in C. elegans. In this study, we used ultraviolet-activated 4,5',8-trimethylpsoralen to induce small deletion mutations. A library of mutagenized worms was prepared for recovery of candidate animals and stored at $15^{\circ}C$ during screening instead of being made into a frozen stock library. In order to isolate deletion mutations in target genes, a polymerase chain reaction (PCR)-based screening method was used. As a result, two independent mutants with deletions of approximately 1.0 kb and 1.3 kb were isolated. This modified and improved reverse genetic approach was proven to be effective and practical for isolating mutant animals to study gene function at the organismal level.

• Journal of Life Science
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• 제9권1호
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• pp.14-16
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• 1999

Genetic variability was monitored by random amplified polymorphic DNA-polymerase chain reaction (RAPD-PCR) in dicofol-susceptible (S), dicofol-resistant (R) and its reverse-selected (RS) strains of two-spotted spider mite, of Tetranychus urticae. Before the reverse-selection, RS strain, selected reversely from R strain, was 23-fold resistance ratio at {TEX}$LC_{50}${/TEX} to S strain. The resistance was started to in incline slowly to the resistance level of S strain after one year, and the resistance ratio was 4-fold in the 7 years after then. PCR-amplification of T. urticae DNA showed polymorphism in the amplifications with 12 primers in 100 kinds of arbitrary DNA sequences. RAPD amplification with primer OPR-12 (5`-ACAGGTGCGT-3`) showed amplified bands at 1,000 base pair in the S-and RS-strain, and at 350 base pair in R-strain. The results of polymorphism are genetic variabilities derived from development and selection of resistance in each strain. The peculiarly amplified fragments were guessed to participate in dicofol resistance. From the analysis of genetic similarity, it is inferred the gene composition of S-and RS-strain is much closer than that of R-strain.

• 한국축산식품학회지
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• 제31권2호
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• pp.158-165
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• 2011

A sensitive reverse transcriptase-PCR (RT-PCR) method to detect viable Escherichia coli O157:H7 in milk was established. The primer sets were designed based on the nucleotide sequences of the rfbE (per) and wbdN genes in the O157 antigen gene cluster of E. coli O157:H7. RT-PCR using five different primer sets yielded DNA with sizes of 655, 518, 450, and 149-bp, respectively. All five of the E. coli O157:H7 strains were detected by RT-PCR, but 11 other bacterial species were not. The sensitivity of RT-PCR was improved by adding yeast tRNA as a carrier to the crude RNA extract. The RT-PCR amplifying the 149-bp DNA fragment was the most sensitive for detecting E. coli O157:H7 and the most refractory to the bactericidal treatments. Heat treatment at $65^{\circ}C$ for 30 min was the least inhibitory of all bactericidal treatments. Treatment with RNase A strongly inhibited the RT-PCR of heated milk but not unheated milk. This study described RT-PCR methods that are specific and sensitive with a detection limit of 10 E. coli O157:H7 cells, and showed that pre-treating milk samples with RNase A improved the specificity to detect viable bacteria by RT-PCR.

• The Plant Pathology Journal
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• 제34권6호
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• pp.575-579
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• 2018

Apple stem grooving virus (ASGV) is considered to cause the most economically important viral disease in pears in Korea. The current PCR-based methods used to diagnose ASGV are time-consuming in terms of target detection. In this study, a novel assay for specific ASGV detection that is based on reverse transcription-recombinase polymerase amplification is described. This assay has been shown to be reproducible and able to detect as little as $4.7ng/{\mu}l$ of purified RNA obtained from an ASGV-infected plant. The major advantage of this assay is that the reaction for the target virus is completed in 1 min, and amplification only requires an incubation temperature of $42^{\circ}C$. This assay is a promising alternative method for pear breeding programs or virus-free certification laboratories.

• The Plant Pathology Journal
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• 제40권4호
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• pp.408-413
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• 2024

The emergence of rice black-streaked dwarf virus (RBSDV) poses a significant threat to global cereal crop cultivation, necessitating the urgent development of reliable detection and quantification techniques. This study introduces a reliable approach for the precise and sensitive quantification of the RBSDV in cereal crop samples, employing a reverse transcription digital polymerase chain reaction (RT-dPCR) assay. We assessed the specificity and sensitivity of the RT-dPCR assay proposed for precise RBSDV detection and quantification. Our findings demonstrate that RT-dPCR was specific for detection of RBSDV, with no cross-reactivity observed with other viruses infecting cereal crops. The RT-dPCR sensitivity was over 10 times that of RT-quantitative PCR (RT-qPCR). The detection limit of RT-dPCR was 0.096 copies/㎕. In addition, evaluation of RT-dPCR assay with field samples was conducted on 60 different cereal crop samples revealed that RT-dPCR (45/60) exhibited superior accuracy compared with RT-qPCR (23/60). In this study, we present a specific and accurate RT-dPCR assay for the detection and quantification of RBSDV.

• 한국분무공학회지
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• 제25권3호
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• pp.132-138
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• 2020

N₂O is hazardous atmosphere pollution matter which can damage the ozone layer and cause green house effect. There are many other nitrogen oxide emission control but N₂O has no its particular method. Preventing further environmental pollution and global warming, it is essential to control N₂O emission from industrial machines. In this study, the thermal decomposition experiment of N₂O gas mixture is conducted by using cylindrical reactor to figure out N₂O reduction and NO formation. And CHEMKIN calculation is conducted to figure out reaction rate and mechanism. Residence time of the N₂O gas in the reactor is set as experimental variable to imitate real SNCR system. As a result, most of the nitrogen components are converted into N2. Reaction rate of the N₂O gas decreases with N₂O emitted concentration. At 800℃ and 900℃, N₂O reduction variance and NO concentration are increased with residence time and temperature. However, at 1000℃, N₂O reduction variance and NO concentration are deceased in 40s due to forward reaction rate diminished and reverse reaction rate appeared.

• Journal of Microbiology and Biotechnology
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• 제13권2호
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• pp.191-195
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• 2003

The in vitro glycosylation of pentapeptide (Arg-Lys-Asp-Val-Tyr; RKDVY) and RNase A was carried out using PNGase F (peptide-N-glycosidase F), and the results were analyzed using MALDI-TOF-MS. Aminated N,N-diretyl chitobiose was used as the sugar in the glycosylation reaction, and the amination yield of N,N'-diacetyl chitobiose was about $60\%$. To reduce the water activity and shift the reaction equilibrium to a reverse reaction, 1,4-dioxane or ethylene glycol was used as the organic solvent in the enzymatic glycosylation. A certain extent of nonenzymatic glycosylaton, known as the Maillard reaction, was also observed, which occurs on an arginine or lysine residue when the length of tie sugar residue is one or two. However, the extent of glycosylation was much higher in the enzymatic reaction, indicating that PNGase F can be effectively used to produce glycopeptides and glycoproteins in vitro.