the advisory committee for biotechnology and 21st century agriculture (ac21) accuracy for...
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The Advisory Committee for Biotechnology and 21st Century
Agriculture (AC21)
Accuracy for Quantitative Testing of Biotechnology Derived Grains
Steven N. Tanner, Director, Technical Services Division
December 5, 2003
▪ Facilitate U.S. grain markets
▪ When testing is needed, ensure reliability and credibility of testing for transgenic grains and oil seeds
GIPSA and Biotechnology
USDA/GIPSA Proficiency Program
▪ Improve the reliability of testing for biotechnology events
▪ 86 organizations now participating
▪ Corn events: T25, CBH351, MON810, GA21, E176, Bt11 and NK603; TC1507 and MON863 to be added in FY 2004
▪ Soybeans: Glyphosate tolerance
USDA/GIPSA Proficiency Program
Global Program
Area Feb 2002 Nov. 2003Africa 0 1Australia 0 1Asia 1 8Europe 5 39 South America 1 10 North America 15 27
Total Participants 22 86
USDA/GIPSA Proficiency Program
▪ Voluntary participation
▪ Participant anonymity
▪ Offered quarterly
▪ Qualitative and quantitative
▪ Results on GIPSA’s biotechnology web page
General Observations▪ Participants use protein and DNA-based tests▪ Qualitative results correct > 90 % of the time
Quantitative Sample Results:▪ Average results were lower than target level ▪ Coefficients of variation (CV’s) ranged from
~30 to >100 %▪ False negatives/positives were < 10 % except at lowest levels (i.e., 0.1 %)
USDA/GIPSA Proficiency Program Observations
Relative Measurement VariabilityAnalyte STD* CV (%)*1 ppb 0.45 45
1 ppm 0.16 16
1 % 0.04 4
DNA-Based Testing** STD Range CV Range0.1 % 0.06-0.50 80-190
1.5 % 0.50-1.15 42-93
5.0 % 1.12-4.20 36-90
*Horwitz predicted values**Actual values reported in Proficiency Program (% by wt)
▪ Methods - Patent Protection/Intellectual Property - Limited official protein-based methods - No globally recognized methods for conventional or real time PCR
▪ Reference Materials - Limited availability - No general agreement (seed, grain,
plasmids, etc.)
Testing Challenges
International Collaboration of Quantitative Methods
Real Time PCR TechniquesDNA Isolation ProceduresDNA Quantitation Technologies
▪ International Reference Materials: GIPSA and NIST Workshop on June 27, 2003
Addressing the Challenges
▪ Protein and DNA reference materials
▪ Matrix reference materials
▪ Global convention for expressing results
GIPSA/NIST Workshop Recommendations
▪ USDA GIPSA▪ NIST▪ Life Science Organizations▪ Institute for Reference Materials and Measurements (IRMM/Europe)▪ National Research Council (NRC/Canada)▪ National Food Research Institute (NFRI/Japan)▪ International Organizations (Codex, ISO, CEN, AOAC-I, AACC, and AOCS)
Key Organizational Cooperation
USDA Biotechnology Webpage
www.usda.gov/gipsa/biotech/biotech.htm