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Activated Partial Thromboplastin Time (APTT, PTT)

Tube type = Light Blue Top

Tube Type

Test ID LAB325
EPIC Order APTT
CPT Code(s) 85730
Group/Individual Test Individual
Laboratory Core Laboratory
Tube Station 30 Routine, 888 STAT
Specimen Routine: 2.7 mL blood/Lt Blue Sodium Citrate tube; See Comments 
Pediatric: 1.8 mL blood/pediatric Lt Blue Sodium Citrate tube
Stability Unspun: 4 hours
Room Temperature: 4 hours
Refrigerated: NO
Frozen: 14 days (plasma only)
Availability Routine: 24 hrs/day
STAT: Yes
Turnaround Time Stat 1 hr, Routine 2 hrs
Reference Range <6 mos: Undefined
>6 mos: 24.8-38.4
Critical: >165 seconds
Comments
  • Deliver Immediately
  • Draw tube must be allowed to fill completely. Short draws will be rejected.
  • Reference Range changes with reagent lot number.

Reviewed by J. Carr on November 19, 2025

UNC Hospitals
McLendon Clinical Laboratories
101 Manning Drive
Chapel Hill, NC 27514