Sample Advice

Serum sampling

All sampling materials are provided by WellFish Diagnostics

Blood samples are taken by the farm following detailed protocols provided by WellFish Diagnostics (training videos and on-site training are provided). All consumables for sampling and sample transportation are provided to ensure safe and rapid transportation to the WellFish laboratory.

Samples are analysed fresh upon arrival in the laboratory. The data generated is interpreted using our bespoke algorithm-based AI models and presented within 24h via our secure, intuitive website portal enabling data informed husbandry decision making.



  • 2 ml syringe and 21G needle (one per fish)
  • Sarstedt serum Micro tube 1.3 ml, with push cap (containing Clotting Activator; Prod Code: 41.1501.005. 
  • 2 ml Eppendorf tubes (numbered to ID individual fish)
  • Centrifuge
  • Sample submission form


  • Fish anaesthetised using MS-222 following manufacturer’s instructions.
  • Whole blood taken from caudal vein, behind caudal fin using 21G (40 mm) needle and 2 ml syringe (new syringe/needle per fish).
  • Pull and replace the syringe plunger to release the pressure before use.
  • Insert the needle behind the caudal fin, towards fish spine. Stop when feel resistance.
  • Gently pull the plunger, watching the syringe fill with blood.
  • Collect 1.5 ml (minimum) to 1.6 ml (maximum) whole blood.
  • Place cap on needle and safely dispose of needle & syringe.
  • Remove needle (important to prevent haemolysis) and aspirate blood into micro tube.
  • Invert tube x3 (do not shake) to mix clotting activator and leave standing upright for a minimum of 30 min before centrifugation (Max time 4 h).
  • Centrifuge at 10,000 g for 5 min.
  • Pipette serum into labelled Eppendorf tube (ensuring not to disturb the blood clot).
  • Ensure Eppendorf tubes containing the serum are closed properly and place into plastic bag.
  • Store cold (4-8oC) until ready for transportation. If freezing place in freezer as soon as possible.
  • Fill in details on Sample Submission Form and include with samples.
  • Email the Laboratory ( when samples on route with estimated time of arrival.


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