For histopathological examinations, it is important to preserve tissue structure to identify disease-related changes and distinguish from postmortem changes (tissue degeneration after death). To ensure optimal sample quality, tissue samples should be collected as soon as possible after euthanasia and immediately placed in formalin.

 

 

Recommended equipment

·         Scalpel, scissors and forceps

·         Sample containers with formalin (can be ordered from Blue Analytics AS → Ordering of sampling kits)

·         Waterproof marker for labelling sample containers

·         Suitable packaging materials for shipment

 

 

Sampling procedure

For general disease investigations, samples should be collected from fish exhibiting clinical signs that are representative of the disease condition. The number of individuals sampled should be adjusted according to the purpose of the investigation.

 

A set of organ samples should be collected from each individual. As a minimum, this should include gills, heart, kidney (preferably head kidney), pyloric caeca with associated pancreatic tissue, liver, spleen and skin/skeletal muscle.

·         If VHS or VNN is suspected in cod, eyes and brain should be included

·         In nephrocalcinosis or HSS is suspected, mid-kidney should be included

·         When sampling whole fry, the abdominal cavity should be opened to ensure adequate penetration of formalin

 

Fixation of tissue samples

Tissue samples must be placed in formalin immediately after collection. To ensure adequate fixation, the formalin must penetrate the tissue before degradation begins. Postmortem changes occur rapidly in the gills, followed by the pyloric region and liver. Gill samples must therefore always be collected as soon as possible after euthanasia.

·         Tissue samples for histopathological examination must not exceed 5 mm in thickness

·         The tissue-to-formalin ratio should be 1:10

·         Tissue samples must be completely submerged in formalin. Avoid overfilling the sample container.

·         Tissue should be handled gently to avoid compression artefacts and other mechanical damage

 

Storage and submission

·         Formalin-fixed samples should be stored and shipped at room temperature. Samples must not be frozen

·         To ensure optimal sensitivity for potential immunohistochemical examinations, samples should be submitted for processing as soon as possible after collection

·         Sample containers must be clearly labelled with relevant sample information and securely packaged to prevent leakage and damage during transport

·         The shipment tracking number must be sent to: mottak@blueanalytics.no

·         Samples may also be delivered directly to Blue Analytics by prior arrangement.

·         A completed Sample submission form histopatology and bacteriology must be placed in a plastic bag and included with every shipment.

 

 

 

Delivery address:

Blue Analytics AS

Kong Christian Frederiks plass 3, entrance A, 1^st floor

5006 Bergen

Norway