NHA Phlebotomy Certification Practice Exam

What is necessary to do with a serum separator tube before shipment?

1. Centrifuge it

2. Mix it thoroughly

3. Refrigerate it

4. Store it at room temperature

The correct answer is: Centrifuge it

Centrifuging a serum separator tube before shipment is essential to separate the serum from the blood cells. When blood is drawn into a serum separator tube, it contains both plasma or serum and cellular components. Centrifugation causes the heavier components, such as red and white blood cells, to settle at the bottom of the tube, while the lighter serum rises to the top and is separated by a gel barrier in the case of a serum separator tube. This separation is crucial for ensuring the integrity and quality of the serum sample when it is sent for testing. If the tube is not centrifuged, the serum and cellular components would remain mixed, which could lead to inaccurate laboratory results due to the presence of cellular material that might alter assays. Other actions, such as refrigeration, mixing thoroughly, or storing at room temperature, might be involved in the handling of blood samples post-collection or prior to testing, but the key step specifically required before shipment of a serum separator tube is the centrifugation to ensure the serum is properly separated from the cells.