Inter-laboratory analysis of selected genetically modified plant reference materials with digital PCR

Area of Science:

• Molecular biology
• Biotechnology
• Food safety

Background:

• Digital PCR (dPCR) is an emerging technology for genetically modified organism (GMO) detection.
• dPCR allows for the absolute quantification of target DNA molecules.
• Established quantitative PCR (qPCR) methods are widely used for GMO analysis.

Purpose of the Study:

• To evaluate the transferability of quantitative PCR (qPCR) assays to digital PCR (dPCR) platforms.
• To compare the performance of two dPCR platforms for absolute GMO copy number determination.
• To assess inter-laboratory variability in GMO quantification using dPCR.

Main Methods:

• Inter-laboratory comparison of two dPCR platforms.
• Testing the performance of qPCR-based methods adapted for dPCR.
• Quantification of absolute GM copy numbers and copy number ratios in certified reference materials.

Main Results:

• Both dPCR systems achieved acceptable variation for measured GMO percentage.
• Higher variability in absolute copy numbers was observed in one-third of cases, attributed to technical factors.
• GMO quantification by dPCR and qPCR yielded comparable results.

Conclusions:

• Validated qPCR assays are generally transferable and suitable for dPCR-based GMO detection.
• dPCR provides a reliable method for absolute GMO quantification.
• Standardized protocols are needed to minimize variability in dPCR-based GMO testing.