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SEED TESTING INTERNATIONAL   www.seedtest.org
ASSOCIATION NEWS 
The overall performance of the nine laboratories 
reporting specific items is shown in Table 1.
The table shows, for each item of the checklist, 
the number of occurrences of the different 
evaluations; additionally, the incidence rate for 
the ‘OK’ score is reported in brackets, based on 
the total number of applicable and non-optional 
cases. Some non-conformities were detected in 
the general section, but since they are not specific 
to GMO testing, they are not discussed 
in detail here.
A low rate of compliance with the ISTA Rules was 
detected when reporting the testing objectives 
(adventitious presence vs trait purity; assessment 
of presence and/or estimation of level) and the 
testing approach (qualitative vs quantitative assay 
on groups or bulks). These are basic definitions 
that clearly and synthetically define the scope 
of testing and that should always be used. The 
testing plan (number of groups/bulks, number of 
flour subsamples per group or bulk, number of 
replicate measurements per flour subsample) was 
often not sufficiently described, and this is also 
related to the inadequate definition of the testing 
approach mentioned above.
A satisfactory level of compliance was found 
instead when defining the testing technology 
(end-point PCR, real-time PCR, LAMP; all 
reporting laboratories used DNA-based assays) 
and the type (pure seed, washed, etc.) and size 
(number of seeds) of the working sample.
On the other hand, the testing targets were 
rarely reported in compliance with the List of 
Standardised Terms[5] adopted by ISTA (based 
on the Biosafety Clearing House and Euginius 
databases). Reporting of the Limit of Detection 
was often incomplete, lacking the specification 
of the unit of measurement, whereas for the Limit 
of Quantification no conclusions can be drawn 
since only two laboratories applied quantitative 
assays. The description of reference materials was 
often inadequate.
Regarding the section concerning the reporting 
of results, the assessment of presence was 
reported correctly most of the time, whereas 
the estimation of level was reported correctly 
only half of the time, including the associated 
confidence intervals.
When looking at the compliance of individual 
laboratories in completing the 14 technical items 
(Table 2), only three (laboratories 4, 5 and 6) 
reached a satisfactory level of correctly reported 
items (≥67 %), with zero or one missing. Three 
laboratories (1, 3 and 8) reached an intermediate 
level (compliance between 38 and 56 %), whereas 
for the other three (laboratories 2, 7 and 9) the 
compliance was insufficient (≤30 %). Of the two 
non-accredited laboratories, one obtained the 
lowest score, while the other was positioned at 
the intermediate level.
Conclusions
Even though this first experiment involved a 
small number of laboratories, it was very useful
since it allowed us to identify several issues in 
reporting GMO testing on ISTA Certificates. 
The conclusions that can be drawn from 
this experiment are important for the full 
implementation of ISTA accreditation based on 
the PBA.
While the ISTA system has the potential to 
provide clarity and uniformity for reporting 
GMO testing results, laboratories must put it into 
practice. The results suggest the following actions 
to support laboratories and improve uniformity 
in reporting:
• Preliminary proposals for amendments to the 
ISTA Rules. These should concern improving 
clarity in section 19.7 (Reporting results), adding 
a definition of ‘testing plan’, and harmonising 
instructions for its reporting in 19.7.1, 19.7.2 
and 19.7.3.
• Based on the checklist developed in this 
exercise, a list of text examples demonstrating 
how each aspect should be correctly reported 
will be compiled. This list will represent a 
useful guide for OIC completion exercises and, 
more importantly, for issuing real OICs. Once 
consolidated, an example on how to report the 
GMO results will be implemented in the ISTA 
Certificate Learning Tool (www.learn-ista.org)  
as already existing for other aspects of seed 
testing. 
• Since reporting the results of GMO testing is 
crucial but also revealed to be rather complex, 
participation in the OIC completion exercise in 
future PTs on GMO will be strongly encouraged, 
even if participants will not be rated.
• The ISTA Accreditation and Technical 
Department intends to implement a system for 
the preparation of evaluation reports in the GMO 
PT database at the ISTA Secretariat.
References
[1] Principles and conditions for laboratory 
accreditation under the Performance Based 
Approach. Available at:
www.seedtest.org/api/rm/TF6EX97X4A3P85W/
acc-d-04-accreditationunderpbav3-0.pdf.
[2] Performance Data Evaluation for the presence 
of seed with specified trait(s) in seed lots. 
Available at: 
www.seedtest.org/api/rm/GF84XM5G6Y24M9Q/
acc-d-05-performancedataevaluation-
1seedlots-v2-1.pdf.
[3] Performance Data Evaluation for Specified 
Trait Purity. Available at: www.seedtest.
org/api/rm/NJ628M8Z936QN27/acc-d-05-
performancedataevaluation-2purity-v1-1.pdf.
[4] ISTA (2026). International Rules for Seed 
Testing. International Seed Testing Association, 
Wallisellen, Switzerland.
[5] Standardised GMO Terms. Available at: 
www.seedtest.org/en/technical-committees/
gmo-committee.html.
Laboratory
GMO
accreditation
OK*
Missing
Incomplete
Inaccurate
Incorrect
Optional
Not
applicable
Total
1
Yes
5
38 %
3
2
2
1
1
14
2
No
1 
8 %
7
1
2
2
1
14
3
Yes
5
56 %
2
1
1
5
14
4
Yes
8
67 %
1
2
1
2
14
5
Yes
8
80 %
1
1
1
3
14
6
Yes
8
80 %
1
1
1
3
14
7
Yes
2
22 %
4
1
1
1
5
14
8
No
5
42 %
4
2
1
2
14
9
Yes
3
30 %
4
1
1
1
4
14
Total
45
46 %
25
12
8
8
3
25
126
Table 2. Performance of individual laboratories in reporting genetically modified organism testing on Orange International Certificates in PT24
*Percentage based on number of applicable and non-optional items

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