Central and Eastern European Workshop on the Detection and Identification of LMOs

POSTED ON BEHALF OF KRASIMIRA IVANOVA
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Dear Participants of the Forum,

I am pleased to welcome you to the first round of online discussions of CEE workshop on the detection and identification of LMOs.

As agreed at the workshop, and outlined in the report of the meeting (which is available at http://www.cbd.int/doc/meetings/bs/bsdiws-2016-01/official/bsdiws-2016-01-02-en.pdf) the Secretariat is organising a series of online discussions for the group to facilitate the consolidation of the knowledge gained during the workshop and encourage the sharing of information between labs within the region.

It is my privilege to moderate the first of these discussions on the topic of sample preparation. As discussed during the workshop this topic will focus on the sharing of practical experiences and knowledge on adequate sample size for various matrices, considerations for adequate sample storage and procedures for sample homogenisation were amongst the issues to be discussed under this topic with the view to develop a reference table to be shared amongst the group.

I would like to invite you to post any relevant material on the matter as well as pose questions and comments on specific areas where additional information is needed so that others that may have this information available can share it with the group.

The discussion will take place for the next two weeks. Your views and feedback will be greatly appreciated. If possible, please post your comments during the early days of the discussion to foster a more lively debate building on the comments of one another.

I look forward to your comments and suggestions!
Kindest regards,
Krasimira

Dear Participants of the Forum,

I would like to remind you that this discussion is open till Monday next week
Sample preparation is the most important step in the process of detection, identification and quantification of LMO`s
I would like to invite you to post here all questions and comments on the topic sample preparation
I have two questions:
What will be a minimal amount of a sample for different sample types and matrices?
How is it connected with the LOD of the methods that we use for the same sample?
Best regards
Krasimira

Dear Forum Participants,
Further to Krasimira's message, I would like to share a couple of resource that I hope would be useful to you in your compilation of information on sample preparation.

1. Sampling for the Detection of Biotech Grains (http://www.gipsa.usda.gov/fgis/biotech/sample2.htm). This page is mainly focused on lot sampling however there is a section that focuses on laboratory sampling and sample preparation.

2. Guidelines for sample preparation procedures in GMO analysis
(http://gmo-crl.jrc.ec.europa.eu/ENGL/docs/WG-SPP-Final-Report.pdf). This document was issued by ENGL as guidance focusing on laboratory sampling.

I am looking forward to seeing additional resources over the next few days.
Kind regards,
Dina

Dear all,
I would like to comment on the very relevant questions posted by Krasimira related to sample size and LOD.
The size of a sample depends on the sample type and matrix, which is well described in the documents posted by Dina. However, it is up to the laboratory (preferably together with the competent authorities) to decide, what is the LOD that should be achieved for the official control. Usually the size of the sample is defined in mass. In cases when the defined mass corresponds to the number of seeds or kernels (e.g. it is indicated that 10 000 maize kernels weights approximately 3 kg) it is important that it is checked in the laboratory if this is valid for each sample. There are different varieties of maize, with different sizes of kernels. If the particular sample is of specific variety with bigger kernels (compared to the average values of maize kernels), there is probably less than 10 000 kernels in the 3 kg sample and this directly influences the theoretical LOD. In such case practical LOD should be compared to the theoretical LOD and the one that is higher should be reported in the certificate.
Kind regards,
Mojca

Thank you Mojca for this information.

My question is what factors could go into a laboratory's decision as to what the LOD should be?

Also when you say that "...it is important that [the number of seeds] is checked in the laboratory if this is valid for each sample" does this mean that you validate the seed:weight ratio before hand or you actually check the number of seeds in every sample received for analysis?

Finally I have also found a few more resources that I hope other participants will find useful and that will serve as input towards the final tables that we will be drafting.

• Sampling of grain and seed to estimate the adventitious presence of biotechnology-derived seeds in a lot. Freese et. al.. Ceareal Foods World  V60, No.1, 2015 (http://www.aaccnet.org/publications/Documents/CFW-60-1-0009-EP.pdf)
Note: This resource is more focused on lot sampling with a very small section on laboratory sampling, however I thought it would be an interesting article for everyone.

• The ITSA International rules for seed testing (http://www.seedtest.org/upload/cms/user/ISTA_Rules_2016_02_sampling1.pdf)

Many thanks
Dina

Thank you Dina for sharing further information on sampling.

Concerning the specific question on the sample size, I would like to further clarify our approach. In our internal rules on the size of the sample it is stated, that the laboratory sample for maize kernels or seeds should weight 3 kg (that corresponds to approximately 10 000 particles). In cases when we receive a sample with lower mass (or sample with bigger seeds) we check the number of particles in the sample by measuring the mass of 100 seeds and extrapolating the number of seeds to the mass of whole sample.

Kind regards,

Mojca