Sample handling

HOW TO PROCESS WHOLE BLOOD, PLASMA AND SERUM SAMPLES

 Whole Blood Use

• Collect¹ sample and transfer^2,4 into the tube containing anticoagulant
• Invert the tube gently 8-10 times to mix anticoagulant into sample.
• Sample ready for use.

 Plasma Sample Harvesting

• Collect¹ sample and transfer^2,4 into the tube containing anticoagulant
• Invert the tube gently 8-10 times to mix anticoagulant into sample.
• Centrifuge⁵.
• Remove liquid fraction above red cells, known as ‘plasma’ for testing. The plasma should be a clear colour; free of haemolysis, lipemia and icterus.

 Serum Sample Harvesting = Red Top (without clot activator, no anticoagulant)

• Collect sample into red top tube and cap. Always collect 2.5 times more sample than required.
• Stand tube upright to allow blood to clot, at room temperature. Clotting time for Feline and Canine is minimum of 20 minutes.
• Remove liquid fraction above the red cells, known as ‘supernatant or serum’ and place into a microcentrifuge tube or similar for centrifuging.
• Centrifuge⁵ ‘serum’ sample.
• Remove serum from tube for testing.

Nurse or Technician is likely to see a small volume of red cell at base of tube after centrifuging.  To store or send on to external laboratory for further testing remove sample from above red cell into another microcentrifuge tube or similar.

1. Ensure enough sample is collected to fill the collection tube to a minimum of 80% volume, and do not overfill the tube.
2. Transfer blood as soon as possible into tube(s) to avoid coagulation.
3. Anticoagulation tube used depends on the analyzer and test(s) performed.
4. If collecting blood into multiple tubes place blood into tubes in the following order: Blue, Gold,

Red, Green, Purple, Grey to avoid carry over of anticoagulant and potential interference. Centrifuge speed, time is specific to centrifuge model. Expect approximately 2,500rpm for 10-15 minutes.

Blue Top = Citrate = Clotting parameters

Green Top = Lithium Heparin = Chemistries

Red Top = Plain = Chemistries

Purple Top = EDTA = Haematology = Whole Blood Only

Grey Top = Floride Oxalate = Glucose, Lactate

Note:     Always run sample as soon as possible.  Refrigerated samples should be warmed to room temperature before testing.  Preferred chemistry sample is plasma unless stated for example Vcheck is serum sample only.  Always label tubes.