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International Seed Testing Association. ISTA’s Position, Experience and Activities in the Field of Biotech Trait Detection. ISTA GMO TF B.R. Kahlert S. Grégoire, C. Haldemann, K. Remund, J.L. Laffont and many others. Outline. What is ISTA? ISTA and of GM Seed Testing Accreditation
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International Seed Testing Association ISTA’s Position, Experience and Activities in the Field of Biotech Trait Detection ISTA GMO TF B.R. Kahlert S. Grégoire, C. Haldemann, K. Remund, J.L. Laffont and many others
Outline What is ISTA? ISTA and of GM Seed Testing Accreditation Proficiency Tests Performance Data Evaluation Audit ISTA can help, ISTA helps to share Workshops, Seedcalc, Website
Objectives of the International Seed Testing Association • The primary purpose of the Association is to develop, adopt and publish standard procedures for sampling and testing seeds, and to promote uniform application of these procedures for evaluation of seeds moving in international trade. • The secondary purposes of the Association are actively to promote research in all areas of seed science and technology, to participate in conferences and training courses aimed at furthering these objectives, and to establish and maintain liaison with other organisations having common or related interests in seed.
ISTA: Laboratories Worldwide More than: • 160 laboratories, • 200 personal members, • originating from 70 countries supporting the association (Government mandates)
ISTA’s major Products & Services • International Rules for Testing Seed • Sampling, Purity, Other Seeds, Germination, Tetrazolium, Seed Health, Species and Variety Testing, Moisture, Coated Seed, Vigour, X-ray • seeds of agricultural & vegetable; flowers, spice, herb & medicinal; tree & shrubs • Proficiency Test Programme • Laboratory Accreditation Programme • International Seed Lot Certificates
ISTA’s Vision & Strategy inTesting of GM Seeds • ISTA Seed Testing Laboratories are competence centres for detection, identification and quantification of GM seeds • ISTA focuses its activity on developing and maintaining a system that ensures reliability and accuracy of results all over the world, when testing for GM seeds – Performance Based Approach defined in the Position Paper: ISTA’s Strategy Regarding Methods for the Detection, Identification and Quantification of Genetically Modified Seeds in Conventional Seed Lots adopted by the Executive Committee Nov. 2001
ISTA’s Actions in Testing of Seed with Specified Trait(s) • Chapter in ISTA Rules for testing of seeds with specified trait(s) • Implementation of Laboratory Accreditation under Performance Based Approach • Organising proficiency tests on detection and quantification of GM seeds in conventional seed • Establishing a system for Performance Data Evaluation for the Presence of Seed with Specified Trait(s) in Seed Lots and Specified Trait Purity • Provide technical help for the laboratories (training courses, workshops, Seedcalc7, ...)
1. Chapter in the ISTA Rules • Rules for the testing of seeds with specified traits including the detection, identification and quantification of GM seeds came into force in February 1st, 2006 • The Rules do not contain specific methods, but define the general principles in testing and reporting results of such tests • Laboratories having methods for GM seed testing in their scope of accreditation can report the test results on the International Seed Analysis Certificate
2. Conditions for ISTA Accreditation under the Performance Based Approach Laboratory ... • Has established method(s) • Defines scope of accreditation • Participates successfully in the ISTA Proficiency Test Programme • Submits performance data • Has an audit
3. Organisation of Proficiency Tests AIMS • to evaluate the performance of participating laboratories • to collect data to be used to set performance standards • To increase experience for ISTA and participating laboratories Satisfactory performance in proficiency tests is a prerequisite for attaining or maintaining the status as an accredited laboratory Laboratories can participate to ISTA proficiency tests, even if they do not seek accreditation
Design of the 6th Proficiency Test • crop: Brassica napus L. • # of samples per lab: 10 • # of negative samples: 3 • # of positive samples: 7 0.3%: 2 0.6%: 3 1.2%: 2 • event: GT73 • sample size: 3300 seeds • Qualitative and Quantitative tests • the laboratory chooses the method
2.4% 5.4% 1.2% 2.0% 0.7% 1.0% Qualitative Test: The detection of GM seeds in samples 49 labs classified each of the 10 samples as either positive or negative. 4 laboratories reported false results. These are 8% of the laboratories. Sample classified as false...
Sub-sampling Quantification Spiking level 0.3% Spiking level 0.6% Spiking level 1.2% Laboratory’s estimated results and its mean Estimate of % GM seeds 12 laboratories reported the test plan... • the size of sub-samples (in number of seeds) • the number of sub-samples tested • the number of positive sub-samples used to compute the result
Quantitative Test 23 laboratories reported the GM content of the positive test samples in % of GM seed by number or by mass or in % DNA copies
Summary PT06 PT06 - Qualitative Results: • The percentage of laboratories reporting correct results for all samples is higher as in the previous tests • >90% of labs made no missclassification, • >97% of samples are reported correctly PT06 - Quantitative Results: • The results show similar variation for the the spiking level (VC = ~50%) • Most laboratories overestimated the true level
Design of the ISTA Proficiency Tests 110 laboratories from 42 countries
PT01 – PT06: Qualitative Tests Percentage of laboratories reporting results correctly or falsely: Percentage of samples reported correctly or falsely: PT01: maize, MON810 & T25; 1% PT02: maize; MON810; 0.7% & 1.4% PT03: maize; MON810 & T25; 0.2%, 2% & 4% PT04: soybean; GTS40; 0.1%, 0.5% & 1.0% PT05: soybean; GTS40 & A2704; 0.2%, 0.5%, 1.0%, 1.5% PT06: rapeseed; GT70; 0.3%, 0.6% & 1.2%
PT01 – PT06: Quantitative Test (Overall) mean of the quantitative test results for each spiking level
PT01 – PT06: Quantitative Test Variation coefficient of the quantitative test results
Summary PT01-PT06 Qualitative Results: Better results when • only one transgenic event involved • transgenic events are well known Better results for negative samples than for positive samples Quantitative Results: Reported values close to the true value • when spiking level between 0.2% and 1.5% • when transgenic event and reference material are well known
How to evaluate the performance of laboratories in ISTA Proficiency Tests? A No problem has been detected in this test B There are small problems, but no specific look or action is suggested to the participant C Problems, ISTA indicates there might be things to consider by the laboratory to explain or correct things BMP Below Minimum of Performance, ISTA indicates that the results were poor and the laboratory need to find explanations and to improve/correct
In-round rating: Presence/absence3 suggested rating systems Example with 10 samples in a Test System3 System1 System2 2 mistakes 2/10=20%
PT06 Rating Qualitative Test (49 labs) Quantitative and Sub-sampling Quantitative Tests (35 labs) RS1: seed number RS2: mass of seed RS3: median
PT01-PT06: In-round Rating % of laboratories which reported an A, B, C or BMP Qualitative Results Quantitative Results
PT01-PT06: Overall Rating Rating System for 6 PTs based on the in-round rating values Qualitative Results Quantitative Results
4. Performance Data Evaluation for presence of seed with specified trait(s) in seed lots and specified trait purity • Laboratory can choose an established and reliable method • The «Performance Based Approach» is used instead of «one ISTA validated method»(not published in the ISTA Rules) • Laboratory needs to demonstrate to ISTA accreditation team its ability to perform well with the method routinely used
Performance Data Evaluation Scope of ISTA Accreditation Performance approved method to be included in lab’s scope of accreditation • must be defined in terms of method used, the species tested, and the specified trait is to be determined
Performance Data Evaluation Relevant PD Documents Evaluation of Performance Data for each combination species, test method and trait! For some combinations a PD has to be performed (on seeds, defined number of samples, defined spiking levels) For other combinations suitable alternative Performance Data may be used(any other data providing effidence that accuracy and repeatability criteria are met)
Performance Data Evaluation Quantification of Trait(s) Range: 0.1% to 3% 7 levels * 4 samples
Performance Data Evaluation Accuracy: departure from true valueRepeatability: variability of results by level 7
Performance Data Evaluation Grading performance 8.2 8.3
Audit • Auditors assess whether implementation aspects are appropriately addressed and whether practice complies with the documented procedures • To that effect, training, equipment management, facilities, reporting and running the overall quality managements system will be assessed • A complete practical demonstration of any performance approved method will not be required
http://www.seedtest.org ISTA Web site