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Test Code TT Thrombin Time

Specimen and Container/Tube

Specimen Type: Plasma

Preferred Specimen: Light Blue Top Tube, 3.2% Sodium Citrate

Other Acceptable specimens: n/a

Volume

Preferred Volume: 1.0 mL

 

Minimum Volume: 0.5 mL

Specimen Stability

Storage Temperature

Stability

Room temperature

4 hours

Refrigerated

not acceptable

Frozen

30 days

Collection Instructions

Collect specimen per standard laboratory collection procedures. 

 

Specimen Handling and Transport Instructions

UCMC Onsite Instructions: 

Collect specimen per standard collection procedure and send to laboratory immediately. 

 

UCMC Offsite and UC MedLab Outreach Instructions: 

  • Centrifuge specimens at >2500 x g for 10 minutes
    at room temperature.
  • Carefully remove plasma from cells using a plastic
    transfer pipette avoiding buffy coat.
  • Aliquot removed plasma into 2 plastic tubes containing a
    minimum of 0.5 mL of specimen in each tube.
  • Plasma samples must then be frozen at -20oC.
  • Once solidly frozen, they must be shipped on dry ice.
    Samples that have thawed in transit will be rejected.

Rejection Criteria

  • Common specimen rejected situations include: incorrect specimen type, insufficient volume, missing or incomplete specimen identifiers, incorrect specimen transport, or specimens outside stability limits. 
  • Specimens that have wrong ratio of blood to anticoagulant (fill volume), clotted or grossly hemolyzed.

Reference Values

 

Test

Age

Sex

Reference Range

Test component

Age range/phase

Male, Female, or all

Insert range

TT

All

All

15.8 - 18.6 seconds

Critical Values

Analyte

Unit

Low

High

Age

n/a

 

 

 

 

Test Components

Thrombin Time (TT)

Clinical Indications

Detecting or excluding the presence of heparin or direct thrombin inhibitors.

Methodology

Clotting

CPT Codes

85670 

LOINC Codes

3243-3

Additional Information

3.2% sodium citrate light blue top tubes must have 9 to 1
ratio of blood to anticoagulant.

Turnaround Time

Turnaround times are relative to the time the specimen is received in the test laboratory. 

STAT Turnaround Time: n/a

 

Routine Turnaround Time: 4 hours

 

Testing Schedule: 7 days a week. 8 am to 10:30 pm

Synonyms/Keyword Search

Thrombin Time

Last Review Date

03/03/2022