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Test Code PTT Partial Thromboplastin Time (APTT), Activated

Important Note

Whole blood specimens have a stability limit of 4 hours.  Platelet-poor sodium citrate plasma (specimens that have been double-spun and aliquoted) have a frozen stability of up to 14 days at -20 degrees or up to 365 days at -70 degrees.

 

Specimens must be filled to the fill line on the vacutainer.  Specimens will be rejected if under- or over-filled.  

Additional Codes

Also known as:

APTT

Specimen Stability Information

 

Specimen Type Temperature Time
Plasma Na Cit Frozen (preferred) 30 days
  Ambient  4 hours

 

PERFORMING LAB

WKMC, WKB, WKP, WKS

Specimen Processing and Handling

Transport whole blood at room temperature if draw to analyze time is expected to be less than 4 hours.

 

If the specimen will be delayed longer than 4 hours, centrifuge specimen for 15 minutes at 2500-3500 rpm. Using a plastic pipette, remove plasma, taking care to avoid the WBC/platelet (buffy) layer and place into an aliquot tube. Spin again, transfer to a new screw-cap vial, then freeze at -20° C. Ship on dry ice.