NHA Certified Phlebotomy Technician (CPT)Specimen HandlingMedium
A phlebotomy technician is preparing to process a blood specimen collected in a light blue top tube for a Prothrombin Time (PT) test. What is the maximum time allowed for this specimen to be centrifuged after collection if it is to be tested for routine coagulation studies?
- A1 hour
- B2 hours
- C4 hours
- D30 minutes
Show answer & explanationAnswer & explanation
Correct answer: B. 2 hours
Specimens collected in light blue top tubes for routine coagulation tests like PT must be centrifuged within 2 hours of collection to ensure accurate results. Delays beyond this time can affect the stability of coagulation factors.
Why the other options are wrong
- A. While some tests might allow 1 hour, routine coagulation tests like PT have a standard maximum of 2 hours for centrifugation.
- C. This timeframe is too long and would likely lead to degradation of coagulation factors, rendering the results inaccurate.
- D. This timeframe is too short for routine coagulation tests and is typically associated with STAT or specialized tests.
Coagulation Specimen Centrifugation Window
The maximum time allowed between blood collection and centrifugation for coagulation specimens (light blue top tubes) to ensure accurate test results.
- Routine PT/aPTT tests require centrifugation within 2 hours.
- Delays can impact coagulation factor stability.
- Proper handling is critical for reliable coagulation test outcomes.
Memory trick: Blue tubes need a quick spin, within two hours, or the results thin.