The aPTT is a screening test that will detect deficiencies or inhibitors to the intrinsic (Factors VIII, IX, XI and XII) and common (Factors II, V, X and Fibrinogen) pathway coagulation factors.
Unopened light blue-top tube: Correct ratio of blood to citrate
is critical. Do not overfill or underfill collection tube. Mix
by inversion 4 times. For non-heparinized patients, maintain
specimen at room temperature. Do not uncap. Stable 24 hours at
Platelet Poor Plasma: Centrifuge light blue-top tube 15 minutes at
approx. 1500 g within 60 minutes of collection. Using a plastic
pipette, remove plasma, taking care to avoid the WBC/platelet buffy
layer and place into a plastic vial.
Centrifuge a second time and transfer platelet-poor plasma into
a new plastic vial. Plasma must be free of platelets (<10,000/mcL).
Freeze immediately and ship on dry ice.
Whole blood: The tubes should be at 100 %+/-10% fill volume in
order to obtain the correct ratio.
Reported (Analytical Time)
The CPT codes provided are based on AMA guidelines and are for informational purposes only.
CPT coding is the sole responsibility of the billing party.
Please direct any questions regarding coding to the payer being billed.
Acceptable: Whole blood sample collected in 3.2% sodium citrate. Proper blood to anticoagulant ratio is required. Reject Criteria: Gross hemolysis; gross lipemia; improper blood to citrate ratio; clotted; high hematocrits; thawed plasma received room temperature or refrigerated Frozen -70 deg C: 6 months Transport Temperature: Frozen Methodology: Photo-Optical Clot Detection