Overview
ISO/TS 21569-6:2026 specifies horizontal methods for the molecular biomarker analysis of genetically modified organisms (GMOs) and their derived products. Part 6 focuses on real-time PCR-based screening methods for detecting the modified cry1Ab/Ac gene and the DNA sequence bridging the maize ubiquitin promoter (Pubi) to the cry1Ab/Ac gene. These sequences are extensively used in genetically modified Bacillus thuringiensis (Bt) plant varieties. The standard outlines laboratory protocols, including sample preparation, DNA extraction, PCR reagent requirements, and amplification conditions, supporting consistent and reliable detection of GMOs in food, feed, and seed samples.
Key Topics
- Real-Time PCR Screening Methods: The document details the use of real-time PCR for qualitative detection of specific DNA sequences associated with the cry1Ab/Ac gene and Pubi-cry construct in GMOs.
- Target Sequences: Focus on identifying the presence of the cry1Ab/Ac gene and the DNA transition region between Pubi and cry1Ab/Ac-key markers in many GM Bt crops.
- Qualitative Detection: These methods are suitable for screening purposes; further analyses may be required to determine specific GMO events or to quantify GMO content.
- Applicability: The protocol applies to DNA extracted from foodstuffs and can also be used for feed and seeds, provided that sufficient amplifiable DNA is obtained from the relevant matrix.
- Validation and Performance: The methods have undergone collaborative international validation, ensuring robustness, high sensitivity, and specificity for the intended target sequences.
- Result Interpretation and Reporting: Comprehensive criteria are provided for indicating positive or negative screening results, including controls and acceptance/rejection thresholds.
Applications
ISO/TS 21569-6:2026 offers significant practical value for laboratories, regulatory agencies, and the food industry by supporting:
- GMO Compliance Screening: Facilitates routine monitoring of food, feed, and seed products for the presence of key genetically modified DNA sequences, as required by global regulations.
- Food Safety and Traceability: Enables regulatory bodies to verify the authenticity and traceability of food and feed products, ensuring correct labeling and compliance with GMO legislation.
- Quality Assurance in Laboratories: Describes validated, standardized procedures, helping laboratories achieve consistent results and align with international best practices.
- Rapid and Reliable Results: By employing real-time PCR, results are generated quickly and with high sensitivity, paralleling the demands of busy testing environments.
Related Standards
ISO/TS 21569-6:2026 integrates with a suite of related ISO standards focused on molecular biomarker analysis and GMO detection, including:
- ISO 21569 - General methods of analysis for the detection of genetically modified organisms
- ISO 21571 - Nucleic acid extraction methods for GMO analysis
- ISO 24276 - General requirements and definitions for GMO analytical methods
- ISO 5725-2 - Guidance on measurement method repeatability and reproducibility
- ISO/IEC 17025 - Competence requirements for testing and calibration laboratories
Summary
By following the protocols specified in ISO/TS 21569-6:2026, laboratories can perform robust, reproducible, and sensitive detection of GMO DNA sequences-specifically cry1Ab/Ac and Pubi-cry-in a wide range of products. This contributes to enhanced food safety, regulatory compliance, and confidence in the results of molecular GMO screening worldwide. For organizations handling or regulating GMO products, aligning with ISO/TS 21569-6:2026 helps ensure results are internationally recognized, consistent, and credible.