• ALGAE
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• 제32권3호
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• pp.189-197
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• 2017

To quantify the abundance of the harmful dinoflagellate Cochlodinium polykrikoides in natural seawaters, we developed the innovative procedure using a droplet digital PCR (ddPCR) with C. polykrikoides-specific primers targeting the internal transcription sequence (ITS). The abundance of C. polykrikoides was estimated by the specific copy number of target ITS DNA segments per cell in cultures and natural water samples. The copy number per C. polykrikoides cell as acquired by ddPCR was $157{\pm}16$, which was evaluated against known cell numbers through a simplified protocol preparing DNAs. The abundances of C. polykrikoides in the waters of different locations estimated by ddPCR agreed with the number of cells visually counted under a microscope. This protocol was used to measure the abundance of C. polykrikoides close to and further off the southern coast of Korea in August of 2016 and 2017. The practical application showed that this method can reduce time for analysis and increase accuracy.

• 생명과학회지
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• 제14권1호
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• pp.32-37
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• 2004

ITS2 부위를 시퀀싱하여 Pseudo-nitzschia delcatissima, P. multiseries, P. pungens, P. subfraudulenta 상호간의 유전자 다양도를 조사함과 아울러 RAPD-PCR pattern을 이용하여 유사도를 구하였다. 유전자 거리를 근거로 했을 때 P. delicatissima 종은 P. multiseries와 P. pungens와는 유전적 거리가 상당히 요원하였고, 심지어 P. subfraudenlta와도 거리를 보였다. 유사도의 경 P. multiseries와 P. pungens는 0.31로 보인 반면에, P delicatissima는 다른 세종과 0.81를 나타내었다. 따라서 P. delicatissima 종은 P. multiseries, P. pungens, P. subfraudulenta와는 유전적으로 밀접하지 않는 관계로 보였다. ITS2부위는 Pseudo-nitzschia 동정에 사용될 수 있는 유용한 도구로 보이며 형태적으로 구분할 수 없는 P. multiseries와 P. pungens을 구분할 수 있다. 또한 RAPD-PCR 방법도 단시간에 Pseudo-nitzchia을 분리시키는데 사용될 것으로 보인다.

• 산업기술연구
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• 제28권A호
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• pp.141-147
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• 2008

Several contaminated bacteria such as Lactobacillus brevis and Pediococcus damnosus in beer production cause beer spoilage by producing off flavours and turbidity. Detection of these organisms is complicated by the strict anaerobic conditions and lengthy incubation times required for their cultivation, consequently there is a need for more rapid detection methods. Recently, two contaminated strains were isolated from vessel of beer production and identified as Lactobacillus species by API kit identificaton as well as 16S-23S ITS sequencing analyses. Two isolated strains were named as Lactobacillus sp. HLA1 and Lactobacillus HLB2, respectively. A polymerase chain reaction (PCR) method was developed for the rapid and specific detection of Lactobacillus sp.. Two sets of primer pairs (HLA1-F/HLA1-R and HLB2-F/HLB2-R) were designed for the amplification of a 1576 base pair (bp) fragment of the HLA1 16S-23S rRNA gene and 1888 bp fragement of the HLB2 16S-23S rRNA. Amplified PCR products were highly specific to detect corresponding bacteria when other contaminated strains were used as PCR templates. However, detection of both strains were limited when $100{\mu}{\ell}$ of cultured samples were mixed with $100m{\ell}$ of beer sample in arbitrary manner. The sensitivity of the assay still needs to be improved for direct detection of the small amounts of bacteria present in beer.

• 한국균학회지
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• 제45권4호
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• pp.386-393
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• 2017

우리나라 양파 재배지의 주요 곰팡이병인 양파 노균병의 원인균 Peronospora destructor를 채집하여, internal transcribed spacer (ITS) 영역을 포함한 4개 유전자의 염기서열을 분석하여 상동성 비교와 분자계통학적 유연관계를 분석하였다. 그 결과, 경남 창녕군, 함안군, 합천군과 전남 무안군, 신안군, 해남군에 발생하는 P. destructor의 4종의 유전자 염기서열 모두 100% 상동성을 보였고, 유연관계 분석에서도 모두 동일한 계통으로 확인되었다. 본 연구에서는 ITS 영역 유전자 염기서열을 이용하여 P. destructor 검출용 PCR법을 개발하였고, 노균병균만을 특이적으로 검출하였다. 또한 식물체를 포함한 total genomic DNA로 검출한계를 검정한 결과, $0.7ng/{\mu}L$까지 가능하였다. 양파 노균병균 검출용 PCR법은 육안상 병징이 나타나지 않을 때도 충분히 감염유무가 확인되었다.

• 한국약용작물학회지
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• 제18권5호
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• pp.329-337
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• 2010

'Angelicae Pubescentis Radix' (APR) is an important oriental medical preparation. In Korea, Aralia continentalis has been recognized as the source plant of APR. Aralia cordata, which is difficult to distinguish from A. continentalis, and Heracleum moellendorffii, which is frequently used in lieu of A. continentalis, are traded in Korean herbal markets. In contrast, in China, Angelica pubescens is recognized as the source plant of APR. In this study, we devised a method not only to discriminate A. contientalis from A. cordata, but also to discriminate both A. contientalis and A. cordata from H. moellendorffii and A. pubescens. Based on the discrepancy in the sequences of specific regions of ITS, we designed a Cont F/ Cont R primer set to amplify a 173 bp PCR band that appears only in A. continentalis. Additionally, we designed an Ara F/ Ara R primer set to amplify a 278 bp PCR band that appears in both A. continentalis and A. cordata. Using these primer sets and the ST R primer to confirm the PCR amplification results, we developed a simple multiplex PCR method for differentiating A. continentalis from A. cordata and to concurrently differentiate both A. continentalis and A. cordata from other APR herbs.

• 한국식품과학회지
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• 제45권2호
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• pp.156-160
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• 2013

우리나라에서 미승인 품목인 유전자변형 감자 EH92-527-1를 검출하기 위한 duplex PCR 검사법이 개발되었다. 감자의 내재유전자로 UDP-glucose pyrophosphorylase (UGP)가 선별되었고, 14개 다른 작물을 이용하여 특이성이 확인되었다. 유전자변형 감자에 삽입된 T-DNA 영역과 감자 게놈 사이의 연결 부위를 증폭하도록 프라이머 EH92-F/R 쌍이 제작되었고, 몇 개의 다른 유전자 변형 작물을 이용하여 특이성이 확인되었다. 서론에서 언급한 바와 같이 BASF사에서 각 개발된 유전자변형 감자 EH92-527-1과 BPS-A1020-5가 GBSS 유전자를 동일하게 포함하고 있으나 본 연구에서 개발한 검사법은 event-specific primers를 이용하였기 때문에 유전자변형 감자 EH92-527-1에만 특이성을 나타낸다. 이와 같이 개발된 duplex PCR 검사법의 검정한계치는 약 0.05%이다. 이러한 duplex PCR 검사법이 우리나라에 미승인 유전자변형 감자의 모니터링에 유용하게 사용될 것으로 판단한다.

• 식물병연구
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• 제10권1호
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• pp.53-57
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• 2004

CGMMV는 한국에서 수박의 주요 병원균이고, 수박 생산에 심각한 영향을 미친다. 이 연구에서는 박 종자의 CGMMV를 RT-PCR을 이용하여 신속하고 민감하게 검정하는 진단방법을 개발하였다. CGMMV-W의 외피 단백질 유전자 sequence에서 제작된 CGMMV에 특이적인 primer인 Wmfl과 Wmrl은 RT-PCR에 의해 420 bp의 증폭산물을 증폭하였다. RT-PCR에 의한 진단을 위하여 바이러스 추출과정을 간소화하고 종자 추출물의 반응 억제물질을 감소시키기 위해 ethanol 침전, double filtration, PEG 침전, phenol/chloroform/isoamyl alcohol에 의한 추출법을 비교하였으며 phenol/chloroform/isoamyl alcohol에 의 한 추출법이 민감성이 강한 방법으로 선발되었다. RT-PCR을 위해 선발된 primer들과 추출법은 1,000립의 건전 종자에 1립의 이병 종자를 혼합한 수준까지 판별이 가능하였다. 신속하고 민감한 RT-PCR에 의한 본 검정방법은 높은 반응 억제물질을 함유하는 박 종자에서 CGMMV의 특이적인 진단을 위해 유용한 방법이다.

• The Plant Pathology Journal
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• 제27권4호
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• pp.385-389
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• 2011

A new reverse transcription loop-mediated isothermal amplification (RT-LAMP) method for the Potato leafroll virus (PLRV) was developed and compared with conventional reverse transcription polymerase chain reaction (RT-PCR) to address its advantages over RTPCR. RT-LAMP primers were designed from the open reading frame 3 (ORF3) sequence of PLRV. The RT-LAMP reactions were conducted without or with a set of loop primers. By real-time monitoring using Turbimeter, the RT-LAMP (with loop primers) detects PLRV in less than 30 min, compared to 120 min of RT-PCR. By adding fluorescent reagent during the reaction, final products of the RT-LAMP were fluorescently visualized under UV light or could be differentiated by naked-eye inspection under normal light. The RT-LAMP was extremely sensitive, about 2000-fold more sensitive than RT-PCR. This study presents great potential of the RT-LAMP for diagnosis and PLRV epidemiology because RT-LAMP method is speedy, sensitive, inexpensive, and convenient.

• 대한전기학회논문지
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• 제39권6호
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• pp.545-556
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• 1990

A design method of a current source using 12-pulse phase-controlled rectifier (PCR) is presented. The critical inductance of the 12-pulse PCR is derived and it is shown that the critical inductance can be reduced using a current source. The control circuit of the 12-pulse PCR with an inner fast dynamic loop is proposed to give the frequency synchronism and to reduce the subharmonics due to the unbalance of the transformer of the power line. This circuit is analyzed and its dynamic loop is optimized. The optimal constant PIMF (proportional, integral and measurable variable feedback, and feedforware) controller is also designed using the time-weighted quadratic performance index. It is shown via experimental results that the proposed design method gives high dynamic and static performance of the current source using the 12-pulse PCR.

• The Plant Pathology Journal
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• 제39권1호
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• pp.141-148
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• 2023

Black shoot blight disease caused by Erwinia pyrifoliae has serious impacts on quality and yield in pear production in Korea; therefore, rapid and accurate methods for its detection are needed. However, traditional detection methods require a great deal of time and fail to achieve absolute quantification. In the present study, we developed a droplet digital polymerase chain reaction (ddPCR) method for the detection and absolute quantification of E. pyrifoliae using a pair of species-specific primers. The detection range was 10³-10⁷ copies/ml (DNA templates) and cfu/ml (cell culture templates). This new method exhibited good linearity and repeatability and was validated by absolute quantification of E. pyrifoliae DNA copies from samples of artificially inoculated immature pear fruits. Here, we present the first study of ddPCR assay for the detection and quantification of E. pyrifoliae. This method has potential applications in epidemiology and for the early prediction of black shoot blight outbreaks.