Tendency for interlaboratory precision in the GMO analysis method based on real-time PCR.

Area of Science:

• Food Science
• Analytical Chemistry
• Biotechnology

Background:

• The Horwitz curve is a standard for interlaboratory precision in chemical analysis.
• Quantitative biochemical methods, like real-time PCR, need similar performance criteria for validation.
• Genetically modified organism (GMO) detection relies on accurate quantitative methods.

Purpose of the Study:

• To establish an analogous criterion to the Horwitz curve for real-time PCR methods used in GMO analysis.
• To analyze the precision of real-time PCR techniques across various genetically modified crops and experimental procedures.
• To propose new models for method performance evaluation in GMO quantitation.

Main Methods:

• Analysis of 53 collaborative studies involving simplex real-time PCR techniques.
• Evaluation of precision (reproducibility and repeatability standard deviation) for GMO amount (%) across seven different GM crops.
• Comparison of precision across studies encompassing DNA extraction and PCR quantitation, or PCR quantitation only.

Main Results:

• Reproducibility standard deviation (SR) and repeatability standard deviation (Sr) for GMO amount (%) were found to be largely independent of the specific GM crop and evaluation steps.
• Proposed equations for SR and Sr as functions of concentration (C): S(R) = 0.1971C^0.8685 and S(r) = 0.1478C^0.8424.
• Developed a method performance index analogous to the Horwitz Ratio for GMO quantitative methods.

Conclusions:

• The precision of real-time PCR for GMO quantitation behaves analogously to the Horwitz curve, being primarily a function of concentration.
• The proposed equations and performance index can facilitate method validation and standardization in GMO analysis.
• These findings support the progressive promotion of method validation for quantitative biochemical methods in food analysis.