Antithrombin III, Func/Immunol

If the patient's hematocrit exceeds 55%, the volume of citrate in the collection tube must be adjusted. Refer to Coagulation Collection Procedures for directions.

015594

Antithrombin III Profile, AT3 Profile; AT-III Profile

Plasma, FROZEN

2 mL

Blood should be collected in a blue-top tube containing 3.2% buffered sodium citrate.[1] Evacuated collection tubes must be filled to completion to ensure a proper blood to anticoagulant ratio.[2,3] The sample should be mixed immediately by gentle inversion at least six times to ensure adequate mixing of the anticoagulant with the blood. A discard tube is not required prior to collection of coagulation samples.[4,5] When noncitrate tubes are collected for other tests, collect sterile and nonadditive (red-top) tubes prior to citrate (blue-top) tubes. Any tube containing an alternate anticoagulant should be collected after the blue-top tube. Serum gel tubes and serum tubes with clot initiators should also be collected after the citrate tubes. Centrifuge and (using a transfer pipette) carefully remove the plasma without disturbing the cells. Transfer the plasma into a LabCorp PP transpak frozen purple tube with screw cap (LabCorp item ID 49482). The specimen should be frozen immediately and maintained FROZEN until tested. To avoid delays in turnaround time when requesting multiple tests on frozen samples, please submit separate frozen specimens for each test requested. Please print and use the Specimen Collection Bulletin as a tube-filling guide.

Blue-top (sodium citrate) tube

FREEZE

Hemolysis; tubes improperly filled; tubes improperly labeled; clotted specimens; thawed specimen