A procedural approach for the identification of sources of uncertainty associated with GM quantification and real-time quantitative PCR measurements

Estimation of measurement uncertainty is important as it provides objective evidence that an assay or instrument is ‘fit for purpose’, and is a requirement for accreditation to ISO17025. Technological developments within the bioanalytical laboratory have progressed rapidly in the past few years. However, the measurement science associated with these technologies has not yet fully matured. The provision of a full measurement uncertainty budget is often difficult because of a lack of standardised approaches and the constraints associated with time, finances and expertise. A procedural approach for the identification of factors that can account for measurement uncertainty in quantification of genetically modified (GM) ingredients using real-time quantitative PCR is presented here. This example illustrates an approach for the identification of factors that can be applied to related assays concerned with GM quantification, can be utilised as part of existing uncertainty approaches, and can provide the basis for making quantitative estimates of uncertainty that will contribute towards a full measurement uncertainty budget.

[1]  Hendrik Emons,et al.  Reliable GMO analysis , 2005, Analytical and bioanalytical chemistry.

[2]  Leonard Steinborn,et al.  International Organization for Standardization ISO/IEC 17025 General Requirements for the Competence of Testing and Calibration Laboratories , 2004 .

[3]  G. Wiseman State of the art and limitations of quantitative polymerase chain reaction. , 2002, Journal of AOAC International.

[4]  Neil Harris,et al.  Event-specific detection of Roundup Ready Soya using two different real time PCR detection chemistries , 2001 .

[5]  Nelson Marmiroli,et al.  Qualitative and quantitative evaluation of the genomic DNA extracted from GMO and non-GMO foodstuffs with four different extraction methods. , 2004, Journal of agricultural and food chemistry.

[6]  Carole A Foy,et al.  Standardisation of data from real-time quantitative PCR methods – evaluation of outliers and comparison of calibration curves , 2005, BMC biotechnology.

[7]  Ilya Kuselman To what extent can an uncertainty calculation be general? , 1998 .

[8]  Marc De Loose,et al.  Use of cloned DNA fragments for event-specific quantification of genetically modified organisms in pure and mixed food products , 2001 .

[9]  P. Corbisier,et al.  Comparison of plasmid and genomic DNA calibrants for the quantification of genetically modified ingredients , 2006 .

[10]  A. Wurz,et al.  Quantitative analysis of genetically modified organisms (GMO) in processed food by PCR-based methods , 1999 .

[11]  Knut G Berdal,et al.  The modular analytical procedure and validation approach and the units of measurement for genetically modified materials in foods and feeds. , 2004, Journal of AOAC International.

[12]  K. Engel,et al.  Distortion of genetically modified organism quantification in processed foods: influence of particle size compositions and heat-induced DNA degradation. , 2005, Journal of agricultural and food chemistry.

[13]  M. Burns,et al.  Analysis and interpretation of data from real-time PCR trace detection methods using quantitation of GM soya as a model system , 2004, Analytical and bioanalytical chemistry.

[14]  P Brodmann,et al.  Validation of PCR methods for quantitation of genetically modified plants in food. , 2001, Journal of AOAC International.

[15]  T. K. Christopoulos,et al.  High-throughput double quantitative competitive polymerase chain reaction for determination of genetically modified organisms. , 2005, Analytical chemistry.

[16]  J. Kristiansen,et al.  Description of a Generally Applicable Model for the Evaluation of Uncertainty of Measurement in Clinical Chemistry , 2001, Clinical chemistry and laboratory medicine.

[17]  Thomas D. Schmittgen,et al.  Analysis of relative gene expression data using real-time quantitative PCR and the 2(-Delta Delta C(T)) Method. , 2001, Methods.

[18]  S. Standard GUIDE TO THE EXPRESSION OF UNCERTAINTY IN MEASUREMENT , 2006 .

[19]  M Vaïtilingom,et al.  Real-time quantitative PCR detection of genetically modified Maximizer maize and Roundup Ready soybean in some representative foods. , 1999, Journal of agricultural and food chemistry.

[20]  G. Berben,et al.  Quantitative determination of Roundup Ready soybean (Glycine max) extracted from highly processed flour , 2005, Analytical and bioanalytical chemistry.

[21]  M. Burns,et al.  An inter-platform repeatability study investigating real-time amplification of plasmid DNA , 2005, BMC biotechnology.

[22]  H. Parkes,et al.  Detection of genetically modified crops and their derivatives: critical steps in sample preparation and extraction. , 2002, Journal of AOAC International.

[23]  F. Nilsen,et al.  Relative transcript quantification by Quantitative PCR: Roughly right or precisely wrong? , 2005, BMC Molecular Biology.

[24]  M. Burns,et al.  Current practice in the assessment and control of measurement uncertainty in bio-analytical chemistry , 2004 .