Antithrombin Ag (ATG)
Department: Coagulation
Test Synonym(s): LAB759, ATG, AT3 Antigen, AT AG, Antithrombin Antigen
CPT Codes: 85301
Methodology: Immunoturbidimetric
Reference Range: 85 - 135%
Tube Type: Light blue top (Sodium Citrate)- 2.7 mL
Specimen: Citrated plasma - platelet poor. This sample requires double centrifugation if sending a plasma aliquot
Alternate Specimen: None
Pediatric Requirements: Peds: 2.7 mL; Neonates: 1.8 mL
Volume: 1.0 mL
Minimum Volume: 1.0 mL
Temperature: Room Temperature for Light blue top tube, must be received within 8 hours of draw. Plasma aliquot(s) must be frozen if not received by lab within four hours of collection.
Stability: Refrigerated: 8 hours, frozen at -70 C: one month
Reasons for Rejection: Clotted sample, incorrectly filled tubes, incorrect tube type, grossly lipemic sample, grossly icteric sample, whole blood >8.0 hours old
Days Performed: Monday - Friday
Times Performed: 8:00 A. - 3:00 PM. Request for inpatient testing must be approved by the Medical Director on call.
TAT: 4 days
Significance: Testing for inherited hypercoagulable states is not recommended on inpatients. Testing should be performed in the outpatient setting. Request for inpatient testing must be approved by the Medical Director on call. Cloudy or lipemic plasma may lead to an underestimation of the antithrombin antigen level.
Special Instructions: Tests for inherited hypercoagulable states is not recommended on inpatients. Indwelling line should be flushed with saline and 5.0 mL of blood discarded before collecting samples for coagulation assays. Tube must be full and not clotted. Deliver to lab immediately. Samples received from an outside lab must be aliquoted and frozen. Samples aliquoted for shipping must be double centrifuged prior to freezing. Grossly hemolyzed, icteric or lipemic samples may be rejected.
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