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Test Code LAB2602 Activated Partial Thromboplastin Time (APTT), Plasma

Additional Codes

Test Name in EPIC EPIC Test Code Soft LIS Ordering Mnemonic



Electromechanical Clot Detection

Specimen Requirements

Specimen Type: Platelet-poor plasma


Preferred: Full Light-blue top (sodium citrate)

Acceptable: Full Sodium Citrate (BD® or Greiner tubes)

Specimen Volume: 1 mL

Specimen Minimum Volume:  0.5 mL

Collection Instructions:

1. Unacceptable specimens: Specimens that are short-draws, over-draws, clotted or hemolyzed may yield incorrect results.

2. If sending from a site spin down, remove top 2/3 of plasma, and spin plasma again in a polyproyplene (cloudy plastic) vial.

3. Aliquot top 3/4 and place platelet-poor plasma in a polypropylene (cloudy plastic) vial.

4. Glass vials are not acceptable for processing/transport/storage.

Additional Information:

1. Double-centrifuged specimens are critical for accurate results as platelet contamination may cause spurious results.

2. Specimen may be held as long as 4 hours before analyzing.

Specimen Transport Temperature

Refrigerate 4 hours/Ambient* 4 hours OK/Frozen 2 weeks at -20°C or 12 months at -70°C


*Ambient 4 hours OK when patient is not on heparin therapy

 Ambient 2 hours OK when patient is on heparin therapy (either Unfractionated (UFH) or Low Molecular Weight (LMW))

Day(s) Test Set Up

Monday through Sunday

Reference Values

Normal range changes every year with lot change of PTT reagent. See patient chart copy for current range.

Test Classification and CPT Coding


Performing Laboratory


Central Region: St. Joseph's Medical Center Lab

East Region: Deer River Hospital Lab, Northern Pines Lab, SMDC Clinical Lab, St. Mary's Hospital -Superior Lab, Virginia Hospital Lab

West Region: Ada Hospital Lab, Fargo Hospital Lab, Fosston Hospital Lab, Holy Trinity Hospital Lab, St. Mary's - Detroit Lakes Hospital Lab