NHA Certified Phlebotomy Technician (CPT)Specimen HandlingHard
A phlebotomy technician is preparing to send a specimen for a prothrombin time (PT) and activated partial thromboplastin time (aPTT) to an off-site laboratory. Which of the following is the correct transport condition?
- ACentrifuge and transport plasma on ice.
- BTransport whole blood at room temperature.
- CCentrifuge and transport plasma at room temperature.
- DTransport whole blood at 37°C.
Show answer & explanationAnswer & explanation
Correct answer: C. Centrifuge and transport plasma at room temperature.
Coagulation specimens for PT/aPTT require prompt separation of plasma from cells. Once separated, the plasma can be transported at room temperature for up to 24 hours for PT and 4 hours for aPTT, or frozen for longer stability. Whole blood should not be transported for extended periods due to cellular metabolism affecting coagulation factors.
Why the other options are wrong
- A. While some specialized coagulation tests require freezing, routine PT/aPTT plasma can be transported at room temperature. Icing plasma is generally not standard for these tests.
- B. Transporting whole blood for PT/aPTT allows cellular metabolism to occur, which consumes coagulation factors and can lead to inaccurate results if delayed.
- D. Transporting whole blood at 37°C would accelerate cellular metabolism and degradation of coagulation factors, leading to highly inaccurate results.
Coagulation Specimen Transport
Coagulation specimens (PT/aPTT) require prompt centrifugation to separate plasma from cells. The plasma can then be transported at room temperature for specific timeframes or frozen for longer storage.
- Separate plasma from cells quickly.
- Plasma can be transported at room temperature (e.g., within 24h for PT).
- Freezing is for longer storage or specific tests.
Memory trick: Coagulation Plasma: Centrifuge, then Carry Calmly.