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Test Code AT3 ACT Antithrombin III Activity Level

Clinical System Name

Antithrombin III Activity Level

Synonyms

A THRMBIN3
Anti Thrombin III Activity
Anti-Thrombin III
AT III Activity
AT3 ACT

Description

For the quantitative determination of the antithrombin activity level in plasma. The test procedure is not affected by therapeutic doses of heparin.  It is therefore suitable for testing of plasmas collected from patients receiving heparin therapy.

Sample Requirements

Specimen: Whole Blood

Container(s): Lt. Blue /Citrate

Preferred Vol :1.8 mL tube

Minimum Vol: N

 

Note: Preferred method of collection is venipuncture with vacuum fill.  Test results are affected by incorrect blood volume.  Use of a Vascular Access Device for the  collection of coag testing is not recommended.

If this method is used it requires a 5 cc clearing volume; 3 cc for size 2 French catheter or smaller. Blood must be trasferred to the  Lt Blue/Citrate tube by use of a  blood transfer device to ensure proper fill. 

Specimen should be centrifuged within 1 hour of collection.

Processing Instructions

Reject due to: Clotted, Hemolyzed, Insufficient quantity, and  Improper collection.

Spin: N

Aliquot: N

Temp: RT

Storage location: Core 6 Freezer  ( -70 C).

 

Note: Deliver blood to Core Coag bench.  Coag Technologist will process. Specimen should be centrifuged within 1 hour of collection. Spin whole blood, remove plasma. Transfer upper 3/4 layer of plasma to plastic tube affixed with large computer label.

 

 

Off-site collection: Preferred method of collection is venipuncture with vacuum fill. Test results are affected by incorrect blood volume. Use of a Vascular Access Device for the collection of coag testing is not recommended. If this method is used it requires a 5 cc clearing volume; 3 cc for size 2 French catheter or smaller. Blood must be trasferred to the Lt Blue/Citrate tube by use of the blood transfer device.

Specimen should be centrifuged within 1 hour of collection. Double spin, transfer upper 3/4 layer of plasma to plastic tube affixed with large computer label. Freeze 2 aliquots of 1.0 mL plasma in plastic tubes at -70C.

Ship frozen on dry ice.

Stability

Specimen Type Temperature Time
Citrated platelet-poor plasma Room temp N
  Refrigerated N
  Frozen   -20C or -70 3 m

 

Availability

STAT Performed TAT
Y Daily 1 h

 

Performing Laboratory

Seattle Children's Laboratory    

 

Department

Department:  Coagulation

Phone Number: 206 987-2578

 

 

 

Reference Range

 

Age %
0 - 1 month 41 - 125
1 mo - 3 mo 48 - 125
3 mo - adult 75 - 125

 

Methodology

Method: Chromogenic Substrate by STA® - Compact Analyzer

Analytical Volume: 0.5 mL plasma 

 

Limitations:  Results affected by moderate lipemia, moderate hemolysis, and moderate icterus.

 Method is affected by improper collection, processing and storage.

High hematocrit greater than or equal to 56% requires a citrate adjusted tube.

CPT Codes

85300