• 제목/요약/키워드: Quantitative detection

검색결과 1,142건 처리시간 0.032초

Event-specific Detection Methods for Genetically Modified Maize MIR604 Using Real-time PCR

  • Kim, Jae-Hwan;Kim, Hae-Yeong
    • Food Science and Biotechnology
    • /
    • 제18권5호
    • /
    • pp.1118-1123
    • /
    • 2009
  • Event-specific real-time polymerase chain reaction (PCR) detection method for genetically modified (GM) maize MIR604 was developed based on integration junction sequences between the host plant genome and the integrated transgene. In this study, 2 primer pairs and probes were designed for specific amplification of 100 and 111 bp DNA fragments from the zSSIIb gene (the maize endogenous reference gene) and MIR604. The quantitative method was validated using 3 certified reference materials (CRMs) with levels of 0.1, 1, and 10% MIR604. The method was also assayed with 14 different plants and other GM maize. No amplification signal was observed in real-time PCR assays with any of the species tested other than MIR604 maize. As a result, the bias from the true value and the relative deviation for MIR604 was within the range from 0 to 9%. Precision, expressed as relative standard deviation (RSD), varied from 2.7 to 10% for MIR604. Limits of detections (LODs) of qualitative and quantitative methods were all 0.1%. These results indicated that the event-specific quantitative PCR detection system for MIR604 is accurate and useful.

Development of a Quantitative Real-time Nucleic Acid Sequence based Amplification (NASBA) Assay for Early Detection of Apple scar skin viroid

  • Heo, Seong;Kim, Hyun Ran;Lee, Hee Jae
    • The Plant Pathology Journal
    • /
    • 제35권2호
    • /
    • pp.164-171
    • /
    • 2019
  • An assay for detecting Apple scar skin viroid (ASSVd) was developed based on nucleic acid sequence based amplification (NASBA) in combination with realtime detection during the amplification process using molecular beacon. The ASSVd specific primers for amplification of the viroid RNA and molecular beacon for detecting the viroid were designed based on highly conserved regions of several ASSVd sequences including Korean isolate. The assay had a detection range of $1{\times}10^4$ to $1{\times}10^{12}$ ASSVd RNA $copies/{\mu}l$ with reproducibility and precision. Following the construction of standard curves based on time to positive (TTP) value for the serial dilutions ranging from $1{\times}10^7$ to $1{\times}10^{12}$ copies of the recombinant plasmid, a standard regression line was constructed by plotting the TTP values versus the logarithm of the starting ASSVd RNA copy number of 10-fold dilutions each. Compared to the established RT-PCR methods, our method was more sensitive for detecting ASSVd. The real-time quantitative NASBA method will be fast, sensitive, and reliable for routine diagnosis and selection of viroid-free stock materials. Furthermore, real-time quantitative NASBA may be especially useful for detecting low levels in apple trees with early viroid-infection stage and for monitoring the influence on tree growth.

Detection and Quantification of Apple Stem Grooving Virus in Micropropagated Apple Plantlets Using Reverse-Transcription Droplet Digital PCR

  • Kim, Sung-Woong;Lee, Hyo-Jeong;Cho, Kang Hee;Jeong, Rae-Dong
    • The Plant Pathology Journal
    • /
    • 제38권4호
    • /
    • pp.417-422
    • /
    • 2022
  • Apple stem grooving virus (ASGV) is a destructive viral pathogen of pome fruit trees that causes significant losses to fruit production worldwide. Obtaining ASGV-free propagation materials is essential to reduce economic losses, and accurate and sensitive detection methods to screen ASGV-free plantlets during in vitro propagation are urgently necessary. In this study, ASGV was sensitively and accurately quantified from in vitro propagated apple plantlets using a reverse transcription droplet digital polymerase chain reaction (RT-ddPCR) assay. The optimized RT-ddPCR assay was specific to other apple viruses, and was at least 10-times more sensitive than RT-real-time quantitative PCR assay. Furthermore, the optimized RT-ddPCR assay was validated for the detection and quantification of ASGV using micropropagated apple plantlet samples. This RT-ddPCR assay can be utilized for the accurate quantitative detection of ASGV infection in ASGV-free certification programs, and can thus contribute to the production of ASGV-free apple trees.

A Novel Marker for the Species-Specific Detection and Quantitation of Shigella sonnei by Targeting a Methylase Gene

  • Cho, Min Seok;Ahn, Tae-Young;Joh, Kiseong;Kwon, Oh-Sang;Jheong, Won-Hwa;Park, Dong Suk
    • Journal of Microbiology and Biotechnology
    • /
    • 제22권8호
    • /
    • pp.1113-1117
    • /
    • 2012
  • Shigella sonnei is a causal agent of fever, nausea, stomach cramps, vomiting, and diarrheal disease. The present study describes a quantitative polymerase chain reaction (qPCR) assay for the specific detection of S. sonnei using a primer pair based on the methylase gene for the amplification of a 325 bp DNA fragment. The qPCR primer set for the accurate diagnosis of Shigella sonnei was developed from publically available genome sequences. This quantitative PCR-based method will potentially simplify and facilitate the diagnosis of this pathogen and guide disease management.

Near-Field Detection of Aβ Proteins Using Micro Beads

  • Lee, Seung-Jun;Sung, Hee-Kyung;Choi, Yo-Han
    • 센서학회지
    • /
    • 제21권5호
    • /
    • pp.319-323
    • /
    • 2012
  • In this paper, we present the possibility of quantification analysis for $A{\beta}$ captured by micro beads using Near-filed detection. In order to evaluate detection efficiency, detected signals were compared with different sizes of micro beads and a varied number of micro beads. Also, $A{\beta}$ deposits and $A{\beta}$ binding to micro beads were measured, therefore, we observed the $A{\beta}$ deposit and light scattering around the surface of micro beads induced by attached $A{\beta}$. This method can be used for quantitative analysis for not only the number of $A{\beta}$, but also the binding ratio of $A{\beta}$ to micro beads.

Collimator Detector Response(CDR) 회복이 적용된 SPECT/CT에서 검출거리에 따른 정량적 정확성 평가 (The Evaluation of Quantitative Accuracy According to Detection Distance in SPECT/CT Applied to Collimator Detector Response(CDR) Recovery)

  • 김지현;손현수;이주영;박훈희
    • 핵의학기술
    • /
    • 제21권2호
    • /
    • pp.55-64
    • /
    • 2017
  • 최근 SPECT/CT의 보급과 함께 다양한 영상보정 방법들을 빠르고 정확하게 적용할 수 있게 되면서, 영상품질 향상과 더불어 정량적 정확성까지 기대할 수 있게 되었다. 그중 Collimator Detector Response (CDR) 회복(recovery)은 검출기면의 거리로부터 발생된 blurring 효과를 보상하여 분해능 회복을 목적으로 하는 보정방법이다. 본 연구에서는 SPECT/CT 영상에서 CDR recovery 가 적용되었을 때 검출거리 변화에 따른 정량적 변화를 알아보고자 하였다. 검출거리의 변화에 따른 획득 계수의 차이를 알아보고자 검출거리를 궤도방식(obit type)에 따라 Circular는 X, Y축 반경 30 cm, Non-Circular는 X, Y축 반경 21 cm, 10 cm, Non-Circular Auto(=Auto Body Contouring_ ABC, spacing limit 1 cm)로 설정하였고, 재구성 방법은 CDR recovery(CDRr)의 사용 유/무에 따른 계수 회복 차이를 알아보고자 OSEM (w/o CDRr)와 Astonish(3D-OSEM with CDRr)로 구분하여 적용하였다. 이 때 감쇠, 산란, 붕괴 보정은 모든 영상에 공통 적용하였다. 정량적 평가를 위해 교정인자(calibration factor_CF) 산출을 목적으로 교정영상(cylindrical phantom, $^{99m}TcO_4$ 123.3 MBq, 물 9293 ml)을 획득하였고, 팬텀 실험을 위하여 50 cc 주사기에 물 31 ml를 채우고 $^{99m}TcO_4$ 123.3 MBq를 설정하여 팬텀영상을 획득하였다. 팬텀 영상에서 주사기 전체 체적에 VOI(volume of interest)를 설정하여 각 조건별로 총 계수 값을 측정하였고, CF를 적용시켜 설정된 참값 대비 추정값의 오차를 구하여 보정에 따른 정량적 정확성을 확인하였다. 산출된 CF는 154.27 (Bq/ml/cps/ml)이며, 각 조건별 영상에서 참값 대비 추정값은 OSEM에서 Circular 86.5%, Non-Circular 90.1%, ABC 91.3% Astonish에서 Circular 93.6%, Non-Circular 93.6%, ABC 93.9%으로 분석되었다. OSEM은 검출거리가 가까울수록 정확성이 높아졌으며, Astonish의 경우에는 거리와 상관없이 거의 유사한 값을 나타내었다. 오차는 OSEM Circular(-13.5%)에서 가장 크고, Astonish ABC(-6.1%)에서 가장 적었다. SPECT/CT영상에서 CDR recovery 적용을 통한 거리보상이 이루어 졌을 때 검출거리가 먼 조건에서도 근접검출과 거의 동일한 정량적 정확성을 보였고, 검출거리의 변화에 영향을 받지 않고 정확한 보정이 가능한 것을 확인 할 수 있었다.

  • PDF

A Design of Snoring Detection System using Chaotic Signal

  • Choo, Yeon-Gyu
    • Journal of information and communication convergence engineering
    • /
    • 제8권5호
    • /
    • pp.560-565
    • /
    • 2010
  • In this study, the existence of chaotic characteristics in snoring signals obtained in the form of time series data was checked through quantitative and qualitative analysis methods, and a snoring signal detection system was designed applied with detection algorithms considering diverse parameters of occurring signals in order to enhance the accuracy and reliability of detections and the performance of the system was checked. The system was tested with certain snoring patients and thereby the results as follows could be obtained.

Quantitative Light-Induced Fluorescence의 이해와 치위생 과정에서의 활용방안 (Quantitative Light-Induced Fluorescence: A Potential Tool for Dental Hygiene Process)

  • 김희은
    • 치위생과학회지
    • /
    • 제13권2호
    • /
    • pp.115-124
    • /
    • 2013
  • Recently, there have been improvements in diagnostic methods for the assessment of early caries lesions. The reason is that dental professionals are seeking methods to reliably detect incipient dental caries and to remineralize them. This review examines the literature on principles, theoretical background, and history of the Quantitative Light-Induced Fluorescence (QLF) system (Inspektor Research Systems BV, The Netherlands). Furthermore, this paper discusses the potential application of QLF system to clinical practice for educational purpose, enabling dental hygiene students to perform oral health assessment using the QLF system. In addition, the clinical application of QLF system can motivate patients by providing additional visual information about caries and bacterial activity. The evidences on validity and reliability of the QLF system for detection of longitudinal changes in de/remineralization and caries were examined. The QLF system is capable of monitoring and quantifying mineral changes in early caries lesions. Therefore, it can be used to assess the impacts of caries preventive measures on the remineralization and reversal of the caries process. And the QLF system is a very promising equipment to assess educational effectiveness for dental hygiene students in their learning process. In conclusion, the QLF system is the most effective technology for more sensitive staging of caries and treatment without surgical intervention.

실시간중합효소연쇄반응을 이용한 유전자변형 콩 가공식품의 정량분석 (Quantitative Analysis of Genetically Modified Soybean in Processed Foods Using Real-time PCR)

  • 민동명;김묘영;정순일;허문석;김진국;김해영
    • 한국식품과학회지
    • /
    • 제36권5호
    • /
    • pp.723-727
    • /
    • 2004
  • 콩 가공식품인 두유, 두부, 비지에서 유전자변형 콩에 삽입된 epsps 유전자의 검출과 정량을 위해 정성과 정량 PCR 방법을 수행하였다. 두유, 두부, 비지에서 유전자변형 콩의 검출은 삽입된 epsps 유전자의 증폭이 크기가 121bp와 330bp가 생성될 수 있는 두 종류의 primer들을 이용하여 0.01%까지 확인하였다. 정량방법은 1, 3, 5%의 유전자변형 콩이 포함된 시료들을 실시간 PCR을 사용하여 유의성 있는 결과를 얻었다. 이러한 결과들은 실시간 PCR 방법을 사용하여 가공식품 내에서 정량적으로 유전자변형 콩을 정량하는데 적용될 수 있음을 보였다.

A Risk Classification Based Approach for Android Malware Detection

  • Ye, Yilin;Wu, Lifa;Hong, Zheng;Huang, Kangyu
    • KSII Transactions on Internet and Information Systems (TIIS)
    • /
    • 제11권2호
    • /
    • pp.959-981
    • /
    • 2017
  • Existing Android malware detection approaches mostly have concentrated on superficial features such as requested or used permissions, which can't reflect the essential differences between benign apps and malware. In this paper, we propose a quantitative calculation model of application risks based on the key observation that the essential differences between benign apps and malware actually lie in the way how permissions are used, or rather the way how their corresponding permission methods are used. Specifically, we employ a fine-grained analysis on Android application risks. We firstly classify application risks into five specific categories and then introduce comprehensive risk, which is computed based on the former five, to describe the overall risk of an application. Given that users' risk preference and risk-bearing ability are naturally fuzzy, we design and implement a fuzzy logic system to calculate the comprehensive risk. On the basis of the quantitative calculation model, we propose a risk classification based approach for Android malware detection. The experiments show that our approach can achieve high accuracy with a low false positive rate using the RandomForest algorithm.