Adventitious Presences Testing

Adventitious Presence (AP) refers to genetically modified organism (GMO) contamination caused by pollen drift/gene flow from one field to another. AP terminology has been accepted by the American Seed Trade Association.  AP testing has become important to companies that supply organic, non-GMO, and low-GMO seed and grain to international customers.  Testing for the absence of genetically modified organisms has become important in overseas sales of conventional planting seed, grain, commodities and organic markets.

We offer a variety of tests to determine the presence of AP material in corn, soybeans, cotton, rice, canola, sugar beets and other crops. These consist of:

• Herbicide Bioassay
• Enzyme Linked Immunosorbant Assay (ELISA)
• Polymerase Chain Reaction (PCR)

In the herbicide bioassay, non-transgenic seeds show distinct characteristics when placed on media that is moistened with the respective herbicide. ELISA detects a specific protein that has been captured by an antibody formed for the protein.  ELISA is capable of quantifying amounts. PCR detects the presence of a certain DNA sequence and can be used to test all crops, tissue or seed resulting in qualitative or quantitative results.

AP testing differs from conventional seed testing by looking for the absence of a specific trait.  Representative sampling of the lot is vital in attaining accurate results. The confidence level of the test becomes higher as the number of seeds tested increases.  For this reason, we pool samples in AP testing to increase the number of individual seeds tested.

Listed below is a table that compares confidence AP levels for the number of seed tested.