Detection Methods

  • Current global regulatory requirements for labelling of products derived from plant biotechnology mean that test methods for the introduced trait(s) have to be developed and validated.
  • Such methods require appropriate reference materials and protocols in order to give accurate and precise identification and quantification of plant biotechnology products.
  • Harmonized guidelines for the validation and use of diagnostic methods are not yet in place.  As a result, numerous governmental agencies and industry organizations are attempting to develop standardization guidelines independently.  Global harmonization of these efforts is necessary to ensure a consistent standard.
  • We therefore encourage and support international coordination of detection methods for plant biotechnology products, and the proper development of guidelines for their use.
  • As part of this commitment, CropLife International and its members have made their detection methods for commercialized biotech-derived products — and related materials and information — available in an online and searchable database.

Testing for the presence of agricultural biotechnology products is being performed on many grain and food products.  The absence of standardized tests can result in inaccurate claims and enforcement actions being taken without a means to challenge the results. Development of reliable, validated methods is necessary to avoid negative economic impacts on trade due to invalid test results.  CropLife member companies work with their direct customers and end users to provide access to diagnostic methods appropriate to their needs, and to encourage international coordination of existing test proficiency and validation efforts

Background

Current global regulatory requirements for labelling of plant biotechnology products derived using recombinant DNA technologies means that test methods to detect the specific proteins or DNA associated with the introduced trait(s) have to be developed and validated.

Such detection methods are an integral part of proper product development, quality control, and regulatory data-gathering for new products.  In addition, such methods are needed by external parties to allow for compliance with international regulations and, when appropriate, to facilitate the segregation and identity preservation of products.

While global regulatory bodies require development of DNA detection methods that allow for unique identification of commercial transgenic events, harmonized guidelines for the validation and use of these methods are not yet in place. As a result, numerous governmental agencies and industry organizations are attempting to develop their own independent standardization guidelines for testing methodologies.

CropLife International therefore believes that the global harmonization of these efforts is necessary to ensure a consistent standard.

Click here to view the policy that our industry supports regarding diagnostic tests for agricultural biotechnology products.

We also support the standardization work being undertaken in the Codex Alimentarius Committee on Methods of Analysis and Sampling to agree consensus criteria for developing methods for detecting biotech material in food.  CropLife supports the current draft general approach and criteria being discussed in this committee and will continue to provide expert input into its further development until completion.  We emphasize the need for such global compatibility of test results in order to facilitate international trade.

PCR as a detection method

Regulatory authorities that operate mandatory labelling schemes for food and feed rely heavily on the Polymerase Chain Reaction (PCR) technique to test for the presence of biotech traits.  While this is a very widely used technique, it is only one of several that are employed for the detection of biotech material in a product.  Nevertheless, it appears to receive the most attention by regulatory agencies outside North America.

The PCR process mimics in vitro the natural process of DNA replication occurring in all cellular organisms – whereby the DNA molecules of a cell are duplicated prior to cell division.  In contrast to natural DNA replication, the DNA reproduction during PCR does not cover the entire sequence of the original DNA molecules but is restricted and targets a specific, relatively short, region of the complete DNA molecules.

The primary use of the PCR technology is to verify the presence or absence of a particular piece of biotech material in a product, or to quantify the amount of biotech material present in a product.  There are many areas to which attention must be paid in order to produce reliable test results.  Because of the very high degree of amplification of traces of genetic material, PCR is prone to false positives and misleading results unless scrupulous attention is paid to avoiding sample contamination. It is critical that such methods are reliable and give the same results in laboratories across the world.  This can only be achieved by proper validation of the methods.

As a tool to assist governments and others to address this issue, a group of seven authors from biotechnology companies, grain traders and private testing laboratories published a peer-reviewed document describing in detail the needs and requirements for a successful application of PCR.  A shorter version with key messages is also available.  This paper – the first review of its kind – has been sent to Codex members and regulatory authorities.