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HelpTest Code LAB324 Thrombin Time
Clinical System Name
Thrombin Time
Synonyms
LAB324
TT
Description
The Thrombin Time is used for the determination of fibrin formation.
Thrombin Times are often the first follow-up test when prolonged PT and/or APTT cannot be explained.
Sample Requirements
Specimen: Whole Blood
Container(s): Lt Blue/Citrate
Required Vol: (1) 1.8 mL or (1) 2.7 mL
Minimum Vol: N
Note: This is enough for a PT, PTT, TT, and Fibrinogen to be run on the same sample.
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. Please review the Coagulation Lab Collection Job Aid for detailed instructions.
Stability
| Specimen Type | Temperature | Time |
|---|---|---|
| Citrated platelet-poor plasma | Room temp | ≤4 h |
| Refrigerated | N | |
| Frozen -20 C or -70 C | ≤3 m |
Availability
| STAT | Performed | TAT |
|---|---|---|
| Y |
Daily |
1 h |
Performing Laboratory
Seattle Children's Laboratory
Department
Department: Coagulation
Phone Number: 206 987-2617 (Client Services)
Methodology
Method: Electromagnetic mechanical clot detection assay by STA-R MAX
Analytical Volume: 100 uL plasma
Limitations: Method is affected by insufficient quantity (underfill), improper collection (overfill), improper processing, and improper storage. High hematocrit greater than or equal to 56% requires a citrate adjusted tube.
Reference Range
| Newborn - 3 Months | 14 - 30 seconds |
| 3 Months - Adult | 15 - 25 seconds |
CPT Codes
85670
Processing Instructions: Main Campus
Deliver whole blood to Coag bench. Coag Technologist will process.
Reject due to: clotted, insufficient quantity (underfill), or improper collection (overfill).
Spin: Y
Aliquot: Y
Storage location: Core 14 Freezer ( -70 C).
Specimen should be centrifuged within one hour of collection. Transfer upper 3/4 layer of plasma to plastic tube affixed with large Epic aliquot label. Do not pool. Assay immediately.
Critical Values
Not defined for this test.
Processing Instructions: Offsite & Regional Clinics
Reject due to: clotted, insufficient quantity (underfill), or improper collection (overfill).
Spin: Y
Aliquot: Y
Storage location: -70 C (preferred) or -20 C.
Specimen should be centrifuged within one hour of collection. Double spin, transfer upper 3/4 layer of plasma to plastic tube affixed with large sample label. Freeze one aliquot of plasma at -70 C (preferred) or -20 C. Preferred plasma volume: 1.0 mL, minimum plasma volume: 0.6 mL. Do not pool.
Non-Children's Hospital Offsite collection: Ship completely frozen on dry ice.
Children's Hospital Reional Clinic collection: Ship completely frozen in frozen Nalgene Labtop cooler with ice pack inside an insulated soft cooler.