Partial thromboplastin time (PTT)
- Test Name:
- Partial thromboplastin time (PTT)
- Synonyms:
-
APTT
- Collection Device/Tube Type:
-
2.7 mL blood - plastic, blue top tube (citrate)
CGY DSC: Pediatric/Neonate: 2.7 mL or 1.8 mL blood - plastic, blue top (citrate)
- Collection Instructions:
-
• Fill collection tube completely
• Immediately mix tube 3-4 times by gentle inversion - Handling/Storage Comments:
-
Samples are stable at room temperature for 8 hours after collection (4 hours for heparinized patients)
• Do not place tubes on ice
Samples must be tested within 8 hours (4 hrs for heparinized patients) of collection
If a delay of >8 hours (> 4 hours for heparinized patients) is expected:
• centrifuge and separate platelet poor plasma
• use plastic pipettes and tubes
• submit frozen platelet poor plasma in a polypropylene aliquot tube, and not a clear plastic polystyrene tube - Frequency of Testing:
-
Daily
- Reference Range:
- 26 - 38 seconds
- Critical Values:
-
Hematology and Coagulation Critical Values
- Last Reviewed:
- 09 May 2023
