• Fisheries and Aquatic Sciences
• /
• v.7 no.3
• /
• pp.130-135
• /
• 2004

The marine dinoflagellate genus Alexandrium, which produces PSP toxins, has a global distribution. As human-assisted dispersal of the species has been suggested, it is important to develop molecular tools to trace the dispersal pathway. To screen population-specific DNA sequences that differentiate Korean and Japanese A. catenella, we targeted the area downstream of the chloroplast psbA gene using PCR with population-specific DNA primers followed by RFLP (restriction fragment length polymorphism) analysis and sequencing. The RFLP patterns of the PCR products divided Korean and Japanese A. catenella regional isolates into three types: Korean, Japanese, and type CMC3, isolated from Korea. We sequenced the PCR products, but found no similar gene in a homology search. The molecular phylogeny inferred from the sequences separated the Korean and Japanese A. catenella strains, as did the RFLP patterns. However, the Japanese isolates included two slightly different sequences (types J and K), while the Korean sequence was the same as the Japanese K type. In addition, a unique sequence was found in the Korean strains CMC2 and CMC3. Population-specific PCR amplification with Japanese A. catenella type-specific PCR primers designed from the type J sequence yielded PCR products for Japanese strains only, showing that the unknown gene can be used for a population analysis of Korean and Japanese A. catenella.

• Journal of Microbiology and Biotechnology
• /
• v.22 no.11
• /
• pp.1467-1470
• /
• 2012

We compared rapid fingerprinting using repetitive sequencebased PCR (rep-PCR) for subtyping Campylobacter jejuni isolates to the widely used multilocus sequence typing (MLST). Representative C. jejuni isolates (n = 16) from broilers were analyzed using MLST and rep-PCR. Both techniques demonstrated an equal discriminatory power of 0.8917, and 9 subgroups were identified. Clonal identification of all 16 isolates was identical for both techniques. The rep-PCR as described in this study may be used as a rapid and cost-effective alternative for subtyping of C. jejuni isolates, or as an effective screening tool in large epidemiological studies.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2006.11a
• /
• pp.359-361
• /
• 2006

As circuits become increasingly complex and devices sizes shrinks, the demands placed on global planarization of higher level. Chemical Mechanical Polishing (CMP) is an indispensable manufacturing process used to achieve global planarity. In the CMP process, Diamond Disk (DD) plays an important role in the maintenance of removal rate. According to studies, the cause of removal rate decrease in the early or end stage of diamond disk lifetime comes from pad surface change. We also presented pad cutting rate (PCR) as a useful cutting ability index of DD and studied PCR trend about variable parameters that including size, hardness, shape of DD and RPM, pressure of conditioner It has been shown that PCR control ability of pressure and shape is superior to RPM and size. High pressure leads to a decrease of cell open ratio of pad surface because polyurethane of pad is destroyed by pressure. So low pressure high RPM condition is a proper removal rate sustain. By examining correlations between RPM and pressure of conditioner, it has been shown that PCR safe zoneto satisfy proper removal rate has the range 0.06mm/hr to 0.12mm/hr.

• International Journal of Oral Biology
• /
• v.42 no.3
• /
• pp.143-147
• /
• 2017

In a previous study, Peptoniphilus mikwangii was isolated from the human oral cavity as a new species. The purpose of this study was to develop P. mikwangii-specific PCR primers. The PCR primers were designed, based on the nucleotide sequence of 16S ribosomal RNA (16S rDNA). The specificity of the primers was tested using genomic DNAs of 3 strains of P. mikwangii and 27 strains (27 species) of non-P. mikwangii bacteria. The sensitivity of primers sensitivity was determined using PCR, with serial dilutions of the purified genomic DNAs (4 ng to 4 fg) of P. mikwangii KCOM $1628^T$. The data showed that P. mikwangii-specific qPCR primers (B134-F11/B134-R1 & B134-F5/B134-R5) could detect only P. mikwangii strains, and 400 fg or 40 fg of P. mikwangii genome DNA. These results suggest that PCR primers are useful in detecting P. mikwangii from the oral cavity.

• Journal of Genetic Medicine
• /
• v.12 no.2
• /
• pp.72-78
• /
• 2015

Recently, noninvasive prenatal test (NIPT) has been adopted as a primary screening tool for fetal chromosomal aneuploidy. The principle of NIPT lies in isolating the fetal fraction of cell-free DNA in maternal plasma and analyzing it with bioinformatic tools to measure the amount of gene from the target chromosome, such as chromosomes 21, 18, and 13. NIPT will contribute to decreasing the need for unnecessary invasive procedures, including amniocentesis and chorionic villi sampling, for confirming fetal aneuploidy because of its higher positive predictive value than that of the conventional prenatal screening method. However, its greater cost than that of the current antenatal screening protocol may be an obstacle to the adoption of this innovative technique in clinical practice. Digital polymerase chain reaction (dPCR) is a novel approach for detecting and quantifying nucleic acid. dPCR provides real-time diagnostic advantages with higher sensitivity, accuracy, and absolute quantification than conventional quantitative PCR. Since the groundbreaking discovery that fetal cell-free nucleic acid exists in maternal plasma was reported, dPCR has been used for the quantification of fetal DNA and for screening for fetal aneuploidy. It has been suggested that dPCR will decrease the cost by targeting specific sequences in the target chromosome, and dPCR-based noninvasive testing will facilitate progress toward the implementation of a noninvasive approach for screening for trisomy 21, 18, and 13. In this review, we highlight the principle of dPCR and discuss its future implications in clinical practice.

• BMB Reports
• /
• v.40 no.3
• /
• pp.444-447
• /
• 2007

Polymerase chain reaction (PCR) is a powerful technique in molecular biology and is widely used in various fields. By amplifying DNA fragments, PCR has facilitated gene cloning procedures, as well as molecular genotyping. However, the extraction of DNA from samples often acts as a limiting step of these reactions. In particular, the extraction of PCR-compatible genomic DNA from higher plants requires complicated processes and tedious work because plant cells have rigid cell walls and contain various endogenous PCR inhibitors, including polyphenolic compounds. We recently developed a novel solution, referred to as AnyDirect, which can amplify target DNA fragments directly from whole blood without the need for DNA extraction. Here, we developed a simple lysis system that could produce an appropriate template for direct PCR with AnyDirect PCR buffer, making possible the direct amplification of DNA fragments from plant leaves. Thus, our experimental procedure provides a simple, convenient, non-hazardous, inexpensive, and rapid process for the amplification of DNA from plant tissue.

• ALGAE
• /
• v.32 no.3
• /
• pp.189-197
• /
• 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.

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

• Asian-Australasian Journal of Animal Sciences
• /
• v.17 no.3
• /
• pp.423-427
• /
• 2004

Seventy-six animals including cattle, sheep, horses, 6 species of zoo animals were employed for collection of fresh feces in order to detect verotoxigenic Esherichia coli (VTEC) by safe, quick and sensitive PCR-based molecular methods. Bacterial cell disruption with bead-beating followed by bacterial DNA purification with hydroxyapatide chromatography and gel filtration allowed DNA preparation from animal feces with high recovery and purity. A mountain goat was firstly shown by PCR and sequencing to shed verotoxin 2 gene (vt2) that was used to generate vt2 probe and second primer set for nested PCR to attempt more sensitive detection. Most sensitive nested PCR revealed that 45% of tested cattle and 47% of tested zoo animals were VTEC-positive, while least sensitive normal PCR detected VTEC from none of these animals except a mountain goat. Moderately sensitive detection by PCR in combination with hybridization suggested that the VTEC density varied between the VTEC-positive cattle.

• Proceedings of the Korean Society for Food Science of Animal Resources Conference
• /
• 2005.05a
• /
• pp.195-198
• /
• 2005

본 연구는 cytochrome B 유전자의 PCR-RFLP 분석기법을 이용하여 다양한 식육자원 및 각종 가공 육제품의 원료육에 대한 정확하고 재현성 높은 축종 및 육종 감별기술을 개발하기 위하여 수행되었다. 국내에서 유통되고 있는 7종류 축종(닭, 양, 돼지, 소, 사슴, 말, 염소)의 육류로부터 cytochrome B 유전자의 특정 염기서열을 포함하는 primer를 설계 제작하여 PCR-RFLP 분석을 실시하였다. 각 축종의 근육조직으로부터 genomic DNA를 추출하고 PCR 증폭 반응을 수행한 후 얻어진 PCR 증폭산물(359 bp)을 두 종류의 제한효소(Hae Ш 및 Hinf I)로 각각 절단한 결과 축종 간 그리고 제한효소 간에 명확한 차이를 보이는 종 특이적인 PCR-RFLP marker를 검출하였다. 따라서, 본 연구에서 개발한 cytochrome B 유전자의 종 특이적 PCR-RFLP marker는 각종 식육 및 가공 육제품의 육종 및 축종 판별에 매우 유용한 DNA marker로 이용될 수 있을 것이다.