The Texas A&M Veterinary Medical Diagnostic Laboratory (TVMDL) performs numerous tests using serum. Proper collection, preparation, and packaging for transportation is imperative to obtaining a quality serum sample. Serum samples that arrive at TVMDL which are hemolyzed and/or lipemic may not be acceptable for testing. Accurate results start with an ideal sample.
Ideal Sample
Clear in appearance and light yellow to straw-like color.
Poor Quality Sample
Cloudy or milky in appearance. Most often due to lipemia and may not be acceptable for testing.
Poor Quality Sample
Pink to red in appearance. Sample is hemolyzed and may not be acceptable for testing.
Additional Guidelines
Utilizing proper collection techniques, allowing sample to clot for 20-30 minutes, centrifugation, and promptly removing the serum from the clot will help ensure a good quality sample.
Samples shipped on the clot run a high risk of yielding a hemolyzed serum sample resulting in the sample being untestable or having altered chemistry values.
It is critical samples be shipped with a cold pack and in an insulated container for overnight delivery. Samples that get warm can grow bacteria, which means a sample that was good when collected could be unacceptable on arrival.
If samples cannot be shipped on the same day they are collected, it’s best practice to centrifuge and pull the serum off the clot. If the sample will be shipped within a day or two, refrigerate the sample. If the sample cannot be shipped soon, freeze the serum. As a reminder, samples that remain on the clot should be refrigerated, not frozen.