scholarly journals Interferences of PCR effectivity: importance for quantitative analyse

2010 ◽  
Vol 27 (Special Issue 2) ◽  
pp. 42-49 ◽  
Author(s):  
J. Hodek ◽  
J. Ovesná ◽  
L. Kučera
Keyword(s):  
Gene Expression ◽  
Real Time ◽  
Genetically Modified Organisms ◽  
Dna Quantification ◽  
Chain Reaction ◽  
Quantitative Analyse ◽  
Pcr Efficiency ◽  
Target Dna ◽  
Polymerase Chain ◽  
Or Gene

Importance of the Polymerase chain reaction (PCR) have already crossed the border of mere target DNA sequence present or absence analysis. For number analyses e.g. Genetically Modified Organisms (GMOs) or gene expression assesment the DNA quantification is demanded. Real-time (or quantitative) PCR is the most used tool for nucleic acids quantification. PCR efficiency has relevant importance on DNA quantification – it should be almost same for each PCR and its value should varied between 90–100%. There are a lot of PCR enhancers and inhibitors well known. We described impact of used DNA solvent and used laboratory plastic on real-time PCR efficiency.

Development of AFLP-derived, functionally specific markers for environmental persistence studies of fungal strains

2006 ◽  
Vol 52 (5) ◽  
pp. 451-461 ◽  
Author(s):  
S S Hynes ◽  
O Chaudhry ◽  
M A Providenti ◽  
M L Smith
Keyword(s):  
Polymerase Chain Reaction ◽  
Real Time ◽  
Genetically Modified Organisms ◽  
Quantitative Polymerase Chain Reaction ◽  
Pcr Primers ◽  
Chain Reaction ◽  
Environmental Persistence ◽  
Fungal Strains ◽  
Target Dna ◽  
Polymerase Chain

The ability to rapidly identify and quantify a microbial strain in a complex environmental sample has widespread applications in ecology, epidemiology, and industry. In this study, we describe a rapid method to obtain functionally specific genetic markers that can be used in conjunction with standard or real-time polymerase chain reaction (PCR) to determine the abundance of target fungal strains in selected environmental samples. The method involves sequencing of randomly cloned AFLP (amplified fragment length polymorphism) products from the target organism and the design of PCR primers internal to the AFLP fragments. The strain-specific markers were used to determine the fate of three industrially relevant fungi, Aspergillus niger, Aspergillus oryzae, and Chaetomium globosum, during a 4 month soil microcosm experiment. The persistence of each of the three fungal strains inoculated separately into intact soil microcosms was determined by PCR analyses of DNA directly extracted from soil. Presence and absence data based on standard PCR and quantification of the target DNA by real-time PCR showed that all three strains declined after inoculation (~14-, 32-, and 4-fold for A. niger, A. oryzae, and C. globosum, respectively) but remained detectable at the end of the experiment, suggesting that these strains would survive for extended periods if released into nature.Key words: Canada domestic substances list (DSL), Canadian Environmental Protection Act (CEPA), genetically modified organisms (GMO), quantitative polymerase chain reaction (qPCR).

scholarly journals Expression of DROSHA and DICER genes in peripheral blood leukocytes in lung sarcoidosis

2018 ◽  
Vol 90 (3) ◽  
pp. 21-24
Author(s):  
I E Malysheva ◽  
O V Balan ◽  
E L Tikhonovich ◽  
T O Volkova
Keyword(s):  
Gene Expression ◽  
Polymerase Chain Reaction ◽  
Real Time ◽  
Peripheral Blood ◽  
Messenger Rna ◽  
Peripheral Blood Leukocytes ◽  
Chain Reaction ◽  
Blood Leukocytes ◽  
Healthy Donors ◽  
Polymerase Chain

Aim. To study the expression level of the genes DROSHA and DICER in peripheral blood leukocytes (PBL) of patients with sarcoidosis of the lungs Materials and methods. The study included 32 patients diagnosed with persistent lung sarcoidosis (mean age 41.56±1.27 years) and 36 healthy donors (control; mean age 42.79±1.95 years). The level of expression of messenger RNA (mRNA) of the genes DROSHA and DICER were determined in PBL of healthy donors and patients with sarcoidosis of the lung by polymerase chain reaction in real time. Results. As a result of the conducted researches it is established that the level of drosha gene expression in PBL patients with sarcoidosis of lungs is significantly reduced in comparison with the control (p

scholarly journals Quantitation of 35S Promoter in Maize DNA Extracts from Genetically Modified Organisms Using Real-Time Polymerase Chain Reaction, Part 2: Interlaboratory Study

2005 ◽  
Vol 88 (2) ◽  
pp. 558-573 ◽  
Author(s):  
Max Feinberg ◽  
Sophie Fernandez ◽  
Sylvanie Cassard ◽  
Chrystèle Charles-Delobel ◽  
Yves Bertheau ◽  
...  
Keyword(s):  
Polymerase Chain Reaction ◽  
Real Time ◽  
Genetically Modified Organisms ◽  
Genetically Modified ◽  
Interlaboratory Study ◽  
Performance Criteria ◽  
Tolerance Interval ◽  
Chain Reaction ◽  
Qrt Pcr ◽  
Polymerase Chain

Abstract The European Committee for Standardization (CEN) and the European Network of GMO Working Laboratories have proposed development of a modular strategy for stepwise validation of complex analytical techniques. When applied to the quantitation of genetically modified organisms (GMOs) in food products, the instrumental quantitation step of the technique is separately validated from the DNA extraction step to better control the sources of uncertainty and facilitate the validation of GMO-specific polymerase chain reaction (PCR) tests. This paper presents the results of an interlaboratory study on the quantitation step of the method standardized by CEN for the detection of a regulatory element commonly inserted in GMO maize-based foods. This is focused on the quantitation of P35S promoter through using the quantitative real-time PCR (QRT-PCR). Fifteen French laboratories participated in the interlaboratory study of the P35S quantitation operating procedure on DNA extract samples using either the thermal cycler ABI Prism® 7700 (Applied Biosystems, Foster City, CA) or Light Cycler® (Roche Diagnostics, Indianapolis, IN). Attention was focused on DNA extract samples used to calibrate the method and unknown extract samples. Data were processed according to the recommendations of ISO 5725 standard. Performance criteria, obtained using the robust algorithm, were compared to the classic data processing after rejection of outliers by the Cochran and Grubbs tests. Two laboratories were detected as outliers by the Grubbs test. The robust precision criteria gave values between the classical values estimated before and after rejection of the outliers. Using the robust method, the relative expanded uncertainty by the quantitation method is about 20% for a 1% Bt176 content, whereas it can reach 40% for a 0.1% Bt176. The performances of the quantitation assay are relevant to the application of the European regulation, which has an accepted tolerance interval of about ±50%. These data were fitted to a power model (r2 = 0.96). Thanks to this model, it is possible to propose an estimation of uncertainty of the QRT-PCR quantitation step and an uncertainty budget depending on the analytical conditions.

Comparison of real-time polymerase chain reaction and end-point polymerase chain reaction for the analysis of gene expression in preimplantation embryos

2006 ◽  
Vol 18 (3) ◽  
pp. 365 ◽  
Author(s):  
Árpád Baji Gál ◽  
Joseph Wallace Carnwath ◽  
Andras Dinnyes ◽  
Doris Herrmann ◽  
Heiner Niemann ◽  
...  
Keyword(s):  
Gene Expression ◽  
Polymerase Chain Reaction ◽  
Real Time ◽  
Reverse Transcription ◽  
Dynamic Range ◽  
Chain Reaction ◽  
Real Time System ◽  
The Real ◽  
End Point ◽  
Polymerase Chain

The aim of the present study was to compare real-time polymerase chain reaction (PCR) and end-point PCR with respect to their suitability for the analysis of gene expression in samples in which the number of cells is limited; for example, in studies of preimplantation embryonic development and to determine the variability of the real-time reverse transcription–PCR assay. The sensitivity, dynamic range and precision of both PCR systems were compared using a single mouse liver cDNA standard. The real-time system was 100-fold more sensitive than the end-point system and had a dynamic range of more than four orders of magnitude. The linear range for end-point PCR extended for two orders of magnitude using a fixed end-point of 31 cycles. The percentage standard error of the mean based on 30 replicates was 0.14% of the threshold cycle (Ct) value for the real-time system and 6.8% for the end-point fluorescence intensity. The coefficients of variation (CV) for reverse transcription combined with real-time analysis and the complete gene expression protocol consisting of mRNA isolation, reverse transcription and real-time PCR analysis were 0.6% and 1.4% of the Ct values, respectively. The present paper details, for the first time, measurement of the biological variation of individual mammalian oocytes. The CV was 1.8% of the Ct value for expression analysis of six bovine oocytes. The results are discussed in relation to the analysis of gene expression in preimplantation embryo development.

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