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What's New In Genetic Testing?

You are viewing the web page of the AOSA GMO Committee. This page was last updated in February 2007.

The purpose of the GMO Committee is to be a resource on issues involving testing for herbicide tolerant or insect resistant traits in seeds. Previously the GMO Committee was the Herbicide Committee and its focus was strictly the testing seed lots for genetic purity (i.e. Roundup Ready®, etc.) or for the unintended presence of herbicide traits. These traits were (and continue to be) either Plant Novel Traits (i.e. developed through traditional plant breeding) or GM traits (developed through the insertion of one or more genes).

Our largest project to date is the Trait Testing chapter which is in the AOSA Cultivar Purity Handbook. The chapter includes an overview of trait testing, sections on PCR testing and on statistical aspects of sampling and testing, step-by-step herbicide bioassay methods for several crops and traits, and instructions for submitting new methods for inclusion in the chapter

NOTE: AOSA and SCST are looking to reduce duplication between the organizations. Currently, SCST has a Genetic Technology Committee which is composed of four working groups: Herbicide Bioassay, Electrophoresis, Immunoassay, and PCR. The future of the GMO Committee is a bit uncertain, but for at least the near future we will be working to update the GMO chapter and be a source of information for developments in genetic testing.

Please contact the GMO Committee with questions or comments about this web page or to contribute material. Click GMO Chapter Information (below) for information about obtaining the AOSA Cultivar Purity Handbook.

Committee Members/Contact Information

GMO Chapter Information

Trait Testing (Certification of genetic analysts)

Upcoming Training and Events

Items in the News

Notes from the Committee
Labs involved in testing for Genetically Modified Organisms (GMOs) aren�t looking for organisms. Rather they look for the presence of genes that are highly desirable when they are supposed to be there. Biotech crops can be tolerant of herbicides, can produce nutrients not normally present in those crops (Vitamin A, protein, etc), and can produce pharmaceuticals without the use of animals or certain manufacturing processes.

We test for GMOs either because we want them there (Genetic Purity testing) or because we don�t (Adventitious Presence or AP testing). GMOs can be detected by several methods. Herbicide tolerant crops can be detected through herbicide bioassay, immunoassay, or PCR. Insect tolerant crops can be tested by bioassay, immunoassay, or PCR. Genetic Purity testing requires quantitative methods (determine percentage of seeds that are tolerant), while AP testing can involve qualitative methods (present or not present), semi-quantitative methods (estimate percentage GMO), or quantitative.

Please contact the GMO Committee with questions or comments about this web page or to contribute material. Click GMO Chapter Infomation (above) for information about obtaining the AOSA Cultivar Purity Handbook and also how to submit herbicide bioassay methods for inclusion in the GMO Chapter.

Committee Chair:
Michael Stahr, CA, CGT Email : mgstahr@iastate.edu
138 Seed Science Center Phone: 515-294-6826
Iowa State University
Ames, IA 50011

Committee Members:
Michael Lovelace          USDA                                       AOSA
Larry Nees                    Indiana State Lab                       AOSA
Aaron Palmer                Arkansas State Lab                   AOSA
Bryan Savoy                 Monsanto                                  SCST
Michael Stahr, chair       Iowa State University                 AOSA/SCST

GMO Chapter Information

Trait Testing (GMO) Chapter Information
The AOSA Cultivar Purity Handbook has been put into an electronic format and includes the trait testing (GMO) chapter.

Chapter contents:

· Overview of testing formats

· Section on statistical considerations for genetic purity and AP testing

· Tables containing information on biotech events and herbicide bioassay methods.

· Herbicide bioassay procedures to test for tolerance to glyphosate (example: Roundup®), glufosinate (Liberty®), chlorsulfuron (STS®), and imazethapyr (Clearfield® crops).

ISTA takes the performance-based approach, which involves not having suggested methods. Rather Labs validate methods (their own or others), have their Lab audited, and participate in proficiency testing. The AOSA Cultivar Purity Handbook, on the other hand, contains methods for several traits and crops which are available for labs just starting out in testing or wishing to expand their testing options. If your organization has a bioassay method that has been validated, consider submitting it (contact Michael Stahr as noted above). Ordering information for the Cultivar Purity Handbook can be found under XXX on the AOSA home page. Contact Jan Osburn

NOTE: The chapter has been updated to reflect a typo in the statistical section and adding a testing method that was inadvertently omitted.

Trait Testing

Certification of Genetic Analysts

Seed analysts have had the opportunity to be certified in purity testing and/or germination testing (AOSA) or purity and germination testing (SCST) for some time. Recently SCST has allowed analysts to be certified in Purity and/or Germination testing. Certifying analysts as genetic technologists has a much shorter history. Currently, SCST offers certification in electrophoresis, herbicide bioassay, immunoassay, and PCR. By achieving certification in one or two areas, a person earns the title of CGT (Certified Genetic Technologist). Certification in three or four areas garners the title of RGT (Registered Genetic Technologist). A person qualifies to take the exams by a combination of experience and education. Exams consist of written portions and a practical portion (if written portions are passed).

You don�t have to be a member of the SCST to take the exams (the AOSA does not offer genetic certification). See the SCST web page for more information (www.seedtechnology.net) or contact Anita Hall (SCST Executive Director): SCST@twcny.rr.com).

Upcoming Training/Informational Events

Genetic Super Workshop – SCST last held a genetic super workshop in February 2005 in Ames, Iowa. It consisted of half or full-day sessions on molecular biology/genetics, electrophoresis, herbicide bioassay, immunoassay, and PCR. Tentative planning is underway for another super workshop that likely will be held in February 2008. Watch the SCST and AOSA web pages for more information.

Genetic Technology Workshop – This one day workshop will be held at Cody, Wyoming on June x, 2007 just days before the start of the AOSA/SCST Annual Meeting. This workshop covers new technologies in genetic testing and will have an opportunity for participants to meet with representatives working with these technologies.

Items of Interest

Genetic Technology Working Group Meetings – Check the AOSA or SCST web pages for meeting times of the working groups of the SCST Genetic Technology Committee during the AOSA/SCST Annual Meeting in Cody, Wyoming. During these meetings current items in testing will be discussed as well as opportunities for participating in referees and other working group activities.

Herculex® RW and XTRA - Lab testing to check for genetic purity of Herculex® RW and Herculex® XTRA corn seed lots is underway. As with BT corn borer, BT root worm, and YieldGard® Plus, testing is done on 96-well ELISA plates. Herculex® I has been available. Herculex® corn is tolerant of glufosinate (Liberty® herbicide).

Roundup Ready® alfalfa – Labs are currently conducting herbicide bioassay tests on alfalfa tolerant to glyphosate herbicide. Testing is done by a spray or substrate imbibition method. A complication of testing alfalfa is its tendency to have higher levels of hard seed than dicot crops such as soybeans. Scarifying the seed by hand or machine will reduce the incidence of hard seed, but may cause mechanical damage to the seed.

Glyphosate-tolerant corn – When testing corn seed lots for presence of seeds tolerant to glyphosate, labs should be aware that immunoassay methods (lateral flow strips, ELISA) won’t detect all glyphosate-tolerant traits. GA21 corn seed (as opposed to NK603 or Roundup Ready® 2 corn), cannot be detected by immunoassay. It can be detected by conducting herbicide bioassay or PCR testing. GA21 was being phased out, but is being used in some corn.
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