• Title, Summary, Keyword: real-time PCR

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Novel Real Time PCR Method for Detection of Plasmodium vivax (새로운 Real Time PCR 방법을 통한 Malaria(Plasmodium vivax)의 검출)

  • Ki, Yeon-Ah;Kim, So-Youn
    • Microbiology and Biotechnology Letters
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    • v.33 no.2
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    • pp.148-153
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    • 2005
  • Malaria is a re-emerging infectious disease that is spreading to areas where it had been eradicated, such as Eastern Europe and Central Asia. To avoid the mortality from malaria, early detection of the parasite is a very important issue. The peripheral blood smear has been the gold standard method for the diagnosis of malaria infection. Recently, several other methods have been introduced for quantitative detection of malaria parasites. Real time PCR that employs fluorescent labels to enable the continuous monitoring of PCR product formation throughout the reaction has recently been used to detect several human malaria parasites. 18S rRNA sequences from malaria parasites have been amplified using Taqman real time PCR assay. Here, a SYBR Green-based real time quantitative PCR assay for the detection of malaria parasite-especially, Plasmodium vivax - was applied for the evaluation of 26 blood samples from Korean malaria patients. Even though SYBR Green-based real time PCR is easier and cheaper than Taqman-based assay, SYBR Green-based assay cannot be used because 18S rRNA cannot be specifically amplified using 1 primer set. Therefore, we used DBP gene sequences from Plasmodium vivax, which is specific for the SYBR Green based assays. We amplified the DBP gene from the 26 blood samples of malaria patients using SYBR Green based assay and obtained the copy numbers of DBP genes for each sample. Also, we selected optimal reference gene between ACTB and B2M using real time assay to get the stable genes regardless of Malaria titer. Using selected ACTB reference genes, we successfully converted the copy numbers from samples into titer, ${\sharp}$ of parasites per microliter. Using the resultant titer from DBP based SYBER Green assay with ACTB reference gene, we compared the results from our study with the titer from Taqman-based assay. We found that our results showed identical tendency with the results of 18S rRNA Taqman assay, especially in lower titer range. Thus, our DBP gene-utilized real time assay can detect Plasmodium vivax in Korean patient group semi-quantitatively and easily.

Design of an Inexpensive Heater using Chip Resistors for a Portable Real-time Microchip PCR System (저항소자를 이용한 휴대형 Real-time PCR 기기용 히터 제작)

  • Choi, Hyoung-jun;Kim, Jeong-tae;Koo, Chi-wan
    • Journal of IKEEE
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    • v.23 no.1
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    • pp.295-301
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    • 2019
  • A heater in a portable real-time polymerase chain reaction(PCR) system is one of the important factors for controlling the PCR thermocycle precisely. Since heaters are integrated on a small-sized PCR chip for rapid heating and fabricated by semiconductor processes, the cost of producing PCR chips is high. Here, we propose to use chip resistors as an inexpensive and accurate temperature control method. The temperature distribution was simulated using one or two chip resistors on a real-time PCR chip and the PCR chip with uniform temperature distribution was fabricated. The temperature rise and fall rates were $18^{\circ}C/s$ and $3^{\circ}C/s$, respectively.

Study on the Enumeration of Legionella in Environmental Water Samples Using Real-time PCR (Real-time PCR을 이용한 환경 중 물 시료의 레지오넬라 분석법 연구)

  • Lee, Jung-Hee;Park, Myoung-Ki;Kim, Yun-Sung;Yun, Hee-Jeong;Lee, Chang-Hee;Jeong, Ah-Yong;Yoon, Mi-Hye
    • Journal of Environmental Health Sciences
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    • v.45 no.5
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    • pp.511-519
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    • 2019
  • Objectives: The standard method for the enumeration of environmental Legionella is culturing, which has several disadvantages, including long incubation and poor sensitivity. The purpose of this study is to demonstrate the usefulness of real-time PCR and to improve the standard method. Methods: In 200 environmental water samples, a real-time PCR and culture were conducted to detect and quantify Legionella. Using with the results of the survey, we compared the real-time PCR with the culture. Results: Each real-time PCR assay had 100% specificity and excellent sensitivity (5 GU/reaction). In the culture, 36 samples were positive and 164 samples were negative. Based on the results of the culture, real-time PCR showed a high negative predictive value of 99%, 35 samples were true positive, 105 samples were true negative, 59 samples were false positive and one sample was a false negative. Quantitative analysis of the two methods indicated a weak linear correlation ($r^2=0.29$, $r^2=0.61$, respectively). Conclusions: Although it is difficult to directly apply quantitative analysis results of real-time PCR in the enumeration of environmental Legionella, it can be used as a complementary means of culturing to rapidly screen negative samples and to improve the accuracy of diagnosis.

Multiplex Real-Time PCR for Simultaneous Detection of 6 Periodontopathic Bacteria (Multiplex Real-Time PCR을 이용하여 6종의 주요 잇몸질환 유발 미생물을 동시에 검출하는 기법)

  • Cho, Hong-Bum
    • Korean Journal of Microbiology
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    • v.49 no.3
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    • pp.292-296
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    • 2013
  • This study utilized an analysis method for detecting six microorganisms, such as Actinobacillus actinomycetemcomitans, Campylobacter rectus, Porphyromonas gingivalis, Tannerella forsythus, Treponema denticola, and Prevotella intermedia, triggering periodontal disease, using multiplex real-time polymerase chain reaction (PCR). The analysis including internal control was made by dividing the six species into two groups using four fluorescence dyes, and it was verified that there was no interference or cross-reaction between the target species and different kinds of oral microbial species. Qualitative and quantitative analyses were conducted on each microorganism in various samples, such as saliva and the plaque, using the multiplex real-time PCR and comparative analysis between periodontitis patients and healthy people, revealing obvious differences between them.

Ultra-Rapid Real-Time PCR for the Detection of Human Immunodeficiency Virus (HIV) (Ultra Rapid Real-Time PCR에 의한 Human Immunodeficiency Virus (HIV)의 신속진단법)

  • Lee, Dong-Woo;Kim, Eul-Hwan;Yoo, Mi-Sun;Han, Sang-Hoon;Yoon, Byoung-Su
    • Korean Journal of Microbiology
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    • v.43 no.2
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    • pp.91-99
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    • 2007
  • For the detection of Human Immunodeficiency Virus (HIV), multiple and ultra-rapid real-time PCR methods were developed. The target DNA sequences were deduced from HIV-1 specific 495bp partial env gene (gi_1184090) and from HIV-2 specific 294 bp partial env gene (gi_1332355), and were synthesized by using PCR-based gene synthesis on the reason of safety. Ultra-rapid real-time PCR was performed by $Genspector^{TM}$ using microchip-based, $1\;{\mu}l$ of reaction volume with extremely short time in each 3 step in PCR. The detection including DNA-amplification and melting temperature analysis was completed inner 15 minutes. The HIV-1 specific 117 bp-long and HIV-2 specific 119 bp-long PCR products were successfully amplified from minimum of template,2.3 molecules of each env gene. This kind of real-time PCR was designated as ultra-rapid real-time PCR in this study and it could be applied not only an alternative detection method against HIV, but also other pathogens using PCR-based detection.

Rapid Detection Method of Avian Influenza Subtype H5N1 using Quick Real-Time PCR (Quick Real-time PCR을 이용한 Avian Influenza Virus Subtype H5N1의 신속검출법)

  • Kim, Eul-Hwan;Lee, Dong-Woo;Han, Sang-Hoon;Kwon, Soon-Hwan;Yoon, Byoung-Su
    • Korean Journal of Microbiology
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    • v.43 no.1
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    • pp.23-30
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    • 2007
  • The most rapid Real-time PCR based detection method for Avian influenza A virus (AIV) subtype H5N1 was developed. The target DNA sequence in this study was deduced from H5N1 subtype-specific 387 bp partial gene of hemagglutinin, and was synthesized by using PCR-based gene synthesis on the ground of safety. Real-Time PCR was performed by $GenSpector^{TM}$ using microchip-based, total $1{\mu}l$ of reaction mixture with extremely short time in each steps in PCR. The detection including PCR-amplication and analysis of melting temperature was totally completed within 13 min. The H5N1-specific 189 bp PCR product was correctly amplified until 2.4 molecules of hemagglutinin gene as minimum of templates. This kind of PCR was designated as Quick Real-Time PCR in this study and it could be applied to detect not only AIV H5N1, but also other pathogens using PCR-based detection.

Comparison of Conventional Culture Method and Real-time PCR for Detection of Yersinia enterocolitica in Sausage and Vegetable Salad (소시지와 야채 샐러드에서 Yersinia enterocolitica 검출을 위한 배지법과 real-time PCR법의 비교)

  • Kim, Yun-Gyeong;Chon, Jung-Whan;Lee, Jae-Hoon;Kwak, Hyo-Sun;Hwang, In-Gyun;Seo, Kun-Ho
    • Korean Journal of Food Science and Technology
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    • v.45 no.1
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    • pp.133-136
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    • 2013
  • The purpose of this study was to compare a conventional culture method and real-time PCR for the detection of Yersinia enterocolitica (Y. enterocolitica) in sausage and in vegetable salad. Food samples inoculated with Y. enterocolitica were enriched in peptone-sorbitol bile-broth, and swabs were then streaked onto cefsulodin-irgasan-novobiocin agar. Biochemical tests for suspected colonies were performed with an API 20E strip. In parallel, real-time PCR was performed, targeting the 16S rRNA gene using 1 mL of enrichment broth. In sausage, the number of positive samples detected by culture method (49 out of 60) was similar (p>0.05) with that of real-time PCR (50 out of 60). However, the number of positive samples of real-time PCR (26 out of 60) was significantly higher (p<0.05) than that of the conventional culture method (6 out of 60) in vegetable salad. Real-time PCR could be an effective screening tool for detecting Y. enterocolitica, particularly in food samples with high levels of background flora, such as a vegetable salad.

A Real Time PCR Assay for Detection and Quantitation of Canine Parvovirus Type 2 in the Feces of Dogs with Parvovirus Infection (실시간 중합효소연쇄반응법을 이용한 개 파보바이러스 감염증의 분변에서 바이러스 정량 분석)

  • koh Min-Soo;Sin So-Yeon;Kim Yong-Hwan;Koh Ba-Ra-Da;Lee Bong-Joo
    • Journal of Veterinary Clinics
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    • v.22 no.4
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    • pp.348-352
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    • 2005
  • We described a rapid, sensitive and reproducible real-time PCR assay for detection and quantitation of canine parvovirus type 2 in the feces of dogs with parvovirus infection. The method was demonstrated to be highly specific and sensitive, allowing a precise canine parvovirus type-2 quantitation over range of eight orders of magnitude from $10^2\;to\;10^9$ copies of standard DNA. Then, fecal samples from parvovirus infected dogs were analyzed by conventional PCR and real-time PCR. Real-time PCR is more sensitive than conventional PCR, allowing to detect low viral titers of CPV-2 in infected dogs. By real-time PCR, a wide range of parvovirus particles was found in the samples from $1.45\times10^6\;to\;9.45\times10^8$ copies/0.01g of feces. However, when dogs are in infection of parvovirus, it is difficult to prove that the numbers of peripheral blood leukocytes are correlated with those of fecal shedding virus.

Detection of Colletotrichum acutatum and C. gloeosporioides by Real Time PCR (Real Time PCR을 이용한 Colletotrichum acutatum과 C. gloeosporioides의 검출)

  • Kim, Seung-Han;Kwon, Oh-Hun
    • Research in Plant Disease
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    • v.14 no.3
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    • pp.219-222
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    • 2008
  • Real time PCR was used to discriminate Colletotrichum acutatum and C. gloeosporioides for analysis of population density. Two primers, caInt2 and cgint, used for conventional PCR to discriminate two species were modified with fluorescent dye to make probe for real time PCR. Fluorescence signals were successfully detected by fCaInt2 and vCgint probe coupled with primer pair Unicon and Unicor1 resulting in discrimination of C. acutatum and C. gloeosporioides by comparison of delta Rn value.

Development of Real-time Quantitative PCR Assay based on SYBR Green I and TaqMan Probe for Detection of Apple Viruses (사과 바이러스 검정을 위한 SYBR Green I 및 TaqMan probe 기반의 real-time PCR 검사법 개발)

  • Heo, Seong;Chung, Yong Suk
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.65 no.4
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    • pp.496-507
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    • 2020
  • Virus infections of apples result in lowered commercial qualities such as low sugar content, weakened tree vigor, and malformed fruits. An effective way to control viruses is to produce virus-free plants based on the development of an accurate and sensitive diagnostic method. In this study, real-time PCR assays based on SYBR Green I and TaqMan probes were developed for detecting ASGV, ASPV, and ApMV viruses. These methods can detect and quantify 103 to 1011 RNA copies/μL of each virus separately. Compared with methods with two different dyes, the SYBR Green I-based method was efficient for virus detection as well as for assay using the TaqMan probe. Field tests demonstrated that real-time PCR methods developed in this study were applicable to high-throughput diagnoses for virus research and plant quarantine.