One of the main activity of the EURL is "to assist actively in the diagnosis of disease outbreaks in Member States by “carrying out confirmatory diagnosis, characterisation and taxonomic or epizootic studies on pathogen isolates" and therefore the EURL is involved in investigations and diagnosis of different cases on request of European NRLs. As the WOAH reference laboratory for Bonamiosis or Marteiliosis diseases the laboratory can also assist diagnostic laboratories from third countries.

: If you need reference material like paraffin blocks, histological slides or DNA suspensions for molecular analysis techniques, please go the Request page in the "Reference Material" section.

Analysis performed & results report

The EURL provide assistance in case of suspicion of EU regulated or emergent mollusc pathogen.

In case of suspicion of EU regulated diseases, confirmatory analyses can include histo-cytology and/or real-time PCR  and/or sequencing, using the methods described in the “diagnostic manual” web page. Histo-cytological analyses are performed under ISO 17025 accreditation (Accreditation n° 1-2160, Scope available on*

Additional methods can be used to characterise pathogens such as conventional PCR, other real-time PCR, in situ hybridization, TEM.

The results  are reported to the laboratory asking for assistance (the applicant) by email. In case of confirmation of presence of a regulated pathogen by the EURL, the applicant must notify its competent authority.

*The EURL does not authorize any reference to its accreditation other than through the full reproduction of the sent result report. 

For any complaint relating to official analyses, the applicant may address it to the EURL, which undertakes to deal with it as soon as possible. The EURL can provide the procedure for handling the complaint upon request.

Requesting assistance

If you need assistance in testing material for a suspected disease, fill in the application/pdf Assistance Request Form. Please send the form before sending any material to EURL. Wait until we contact you.

When completing the form, it is very important to provide the maximum of information about the samples. Please also enter the geographic coordinates of the sampling area in the WGS84 standard like the following example:

  • Latitude: 45,480828N
  • Longitude: 01,105529W

Packing and sending the material

To be sure that the material will reach our laboratory in good condition, please respect the following advices on how to correctly pack the items.  Our address is:

EURL for mollusc diseases
Av. de Mus de Loup
17390 La Tremblade

Sending material for histo-cytology / ISH analyses

Paraffin blocks

Wrap the paraffin blocks in paper towel to protect the side with tissue. Put the blocks in a plastic bag. Finally put the bag in the parcel protected by polystyrene chips or protective bubble wrapping.

Histological slides

Histological sections should include the maximum of mollusc organs. Put the slides in a slide jar or slide mailer or a small slide storage box depending on the number of slides you want to send. Wedge the slides with paper towel if needed. Put the first box in a second one and wedge it with polystyrene chips or paper. Finally put the second box together with polystyrene chips or protective bubble wrapping in the parcel you are sending.

Fixed tissue for histology (not recommended, only if you cannot perform histological analysis in your laboratory)

Remove the tissue from the fixative and wrap it in a piece of paper towel, then put it in a plastic bag with double-track zipper. Do not forget to put a label on each bag. Put all the bags inside a bigger plastic bag to be sure that no liquid can leak. Finally put this last bag together with polystyrene chips or protective bubble wrapping in the parcel you are sending.

Sending samples for molecular biology analyses

Organs to be analysed depend on the pathogens for which analysis is carried out.

We recommend sending pools of tissues of digestive gland, gills and mantle  for each animal (or DNA extracted from theses tissues) in order to allow analyses of the main mollusc pathogens.

If not possible, analysis should be done at least on the following organs:

Suspicion of


Marteilia refringens

Digestive gland

Bonamia ostreae and/or Bonamia exitiosa


Perkinsus marinus

Mantle or gills

Mikrocytos mackini

Pustule/bump if present or mantle

For other pathogens, please refer to the corresponding PCR SOP to know which organs should be targeted for analysis

Fixed tissue for molecular biology

Put the small tissue pieces (at least 20 mg) in the fixative (e.g. absolute ethanol / 95% ethanol) in microtube equiped with screw cap with silicone seal. Tissues should be fully immerged in ethanol. Eventually use Parafilm® to reinforce the sealing. Do not forget to put a label with sample ID on each tube. Put the tubes in a sealed container such as plastic bag with double-track zipper or a 50 ml tube. Finally put the bag protected by polystyrene chips in the parcel you are sending.

DNA suspension

Put the DNA suspension (at least 20µl - more if possible)  in eppendorf tubes sealed with Parafilm®, or in microtube equiped with screw cap with silicone seal. Do not forget to put a label with sample ID on each tube. Put the tubes in a sealed container such as plastic bag with double-track zipper. To preserve DNA, samples should be sent frozen or at controlled cool temperature (generally <8°C)