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Test Code PTT/LAB5157 Activated Partial Thromboplastin (APTT), Plasma

Performing Laboratory

Asante Rogue Regional Medical Center / Asante Three Rivers Medical Center

Specimen Requirements

Blue top tube - Refer to ORDER OF DRAW      Order of Draw


Note:  The ratio of blood to anticoagulant is critical.

Vacutainers must draw their full volume.

Syringe Draw:     

4.5 mL blood in 5 mL Blue top tube

2.7 mL blood in 3 mL Blue top tube

1.8 mL blood in 2 mL Blue top tube


Specimens will not be accepted if tubes are not filled to their correct volume.

If multiple tests are drawn, draw coagulation studies first or second

Specimen Transport Temperature and Stability

Specimen stable 4 hours unopened or opened, room temperature or refrigerated

Specimen Minimum Volume

1 properly filled 2 mL Blue top tube

Reasons for Rejection

Quantity not sufficient (QNS)

Specimens not filled to correct volume

Lacking Two Patient Identifiers:

         1-Patient's First & Last name 

         2-Patient's Date of Birth

Day(s) Test Set Up

Monday through Sunday

Routine - same day

ASAP - 2 hours after receipt of specimen in lab

STAT - 1 hour after receipt of specimen in lab

Additional Information

Evaluation of intrinsic coagulation system, useful in monitoring heparin therapy. 

Aids in screening for presence of classical hemophilia A and B; Christmas disease; congenital deficiencies of Factors II, VI, VIII, IX, X, XI and XII; dysfibrinogenemia; vitamin K deficiency; congenital deficiency of Fitzgerald factor; congenital deficiency of prekallikrein (Fletcher factor).


Not recommended for danaparoid, low molecular weight heparin monitoring.

(use Factor Xa inhibition if needed)


Turbidimetric clot detection by measuring change in optical density

Performing Department


Test Classification and CPT Coding


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