19
SEED TESTING INTERNATIONAL OCTOBER 2026
 ASSOCIATION NEWS 
Table 1. Overall completion of the 16 items of the checklist by the nine laboratories reporting genetically modified organism results on Orange International 
Certificates in PT24
*Percentage based on number of applicable and non-optional items
Type 
of item
Item
OK*
Missing
Incomplete
Inaccurate
Incorrect
Optional
Not
applicable
Total
General
01-Stated by the applicant
8
89 %
1
9
Technical
02-Information
6
67 %
3
9
03-Objective 1
1
11 %
7
1
9
04-Objective 2
3
33 %
3
1
2
9
05-Testing approach
2
22 %
4
1
2
9
06-Testing technology
8
89 %
1
9
07-Working sample description: type and size
7
78 %
1
1
9
08-Testing plan
3
43 %
4
2
9
09-Testing targets
2
22 %
7
9
10-LOD
3
33 %
1
5
9
11-LOQ
1
50 %
1
7
9
12-Reference materials
4
44 %
2
2
1
9
13-Reporting results: assessment of presence
7
78 %
2
9
14-Probability statement on negetive 
qualitative result
0 
0 %
3
6
9
15-Reporting results: estimation of level
2
50 %
2
5
9
16-Reporting results: confidence interval/
probability statement
2
50 %
2
5
9
Total
59
50 %
28
13
8
8
3
25
144
was to assess the competence of laboratories 
in reporting GMO testing results according to 
the established rules, and to identify potential 
actions from both sides (laboratories and ISTA)  
to enhance clarity and uniformity.
Orange International 
Certificate Completion 
Exercise
PT24 concerned the assessment of presence 
and the estimation of level (the latter for the 
laboratories accredited for this objective or those 
willing to perform this part voluntarily)  
of glufosinate-tolerant T25 event (ACS-ZMØØ3-2) 
in Zea mays. Eight 1500-seed samples containing 
either 0.0, 0.26, 0.53 or 0.93 % GM seeds were 
randomly coded and shipped to 33 laboratories 
for testing.
Participation in the OIC completion exercise 
was restricted to ISTA member laboratories and 
was voluntary even for those accredited for GMO 
testing. Of the 31 participants that submitted 
their results, nine ISTA accredited member 
laboratories (seven of which were also accredited 
for GMO testing) returned their ‘specimen’ OIC 
filled in. Laboratories were required to report 
the results for sample 1, regardless of whether 
it contained GM seeds. As for standard PTs, 
in addition to the description of analysis and 
results, the exercise included a general part 
concerning reporting of information under the 
responsibility of the applicant or of the testing 
laboratory / sampling entity.
To ensure a methodical and uniform evaluation 
of the certificates, a checklist of 16 items, of 
which two were general and 14 technical, was 
created. The corresponding information was then 
searched for in each certificate and extracted, 
if present. For each item, one of the following 
evaluations was given:
• OK = necessary information provided in the 
correct manner
• Missing = information completely missing
• Incorrect = information provided is incorrect
• Incomplete = information provided is correct 
but incomplete
• Inaccurate = information provided but not 
accurate
• Optional = information not strictly necessary
• Not applicable = information not expected from 
the laboratory based on the testing objectives
The assessment was performed independently by 
three technical experts. A consensus evaluation 
was then reached, and the assessment was 
finally reviewed by the ISTA Accreditation and 
Technical Department, particularly regarding 
the general part of reporting on the OIC.
For each item, evaluations and explanatory 
notes were compiled in a report and sent to 
the participating laboratories by the GMO PT 
coordinator. It is worth noting that the evaluation 
of this exercise does not influence the rating of 
laboratories based on their submitted analytical 
results for the eight samples (i.e. the exercise  
of completing the OIC specimens is not rated).
Results
A preliminary review of the certificates revealed 
a wide range of reporting styles among the nine 
laboratories (Fig. 1).
Some laboratories were very synthetic and 
schematic, while others were detailed and wordy. 
Furthermore, there was a substantial variation 
among laboratories in the sequence in which 
different pieces of information were reported.

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