Development and validation of an event-specific quantitative PCR method for genetically modified maize MIR162

Area of Science:

• Molecular Biology
• Biotechnology
• Agricultural Science

Background:

• Accurate quantification of genetically modified organisms (GMOs) is crucial for regulatory compliance and international trade.
• Existing methods may lack specificity or require extensive validation for novel events.
• The MIR162 maize event requires reliable analytical methods for detection and quantification.

Purpose of the Study:

• To develop and validate a novel real-time PCR-based method for event-specific quantification of the GM maize event MIR162.
• To determine the conversion factor (Cf) for accurate GMO amount calculation using different real-time PCR instruments.
• To assess the method's performance in terms of trueness and precision through an interlaboratory study.

Main Methods:

• Development of a standard plasmid for MIR162 quantification.
• Empirical determination of conversion factors (Cf) for Applied Biosystems 7900HT (ABI7900) and 7500 (ABI7500) real-time PCR instruments.
• Validation through a blind interlaboratory study evaluating bias and reproducibility (RSDr).

Main Results:

• Established Cf values of 0.697 for ABI7900 and 0.635 for ABI7500.
• Achieved biases below 25% and reproducibility relative standard deviation (RSDr) values below 20% across all tested concentrations.
• Determined a limit of quantification of 0.5% for the developed method.

Conclusions:

• The developed real-time PCR method provides accurate and precise event-specific quantification of MIR162 GM maize.
• The method is validated for practical application in GMO detection and quantification.
• The established Cf values and performance metrics ensure reliable analysis across different platforms.