Test Code HTT Thrombin Time, Heparin Removed
Specimen and Container/Tube
Specimen Type: Plasma
Preferred Specimen: Light Blue Top Tube, 3.2% Sodium Citrate
Other Acceptable specimens: N/A
Specimen Handling and Transport Instructions
UCMC Onsite Instructions:
Collect specimen per standard collection procedure and send to laboratory immediately.
NOTE: Once each blue top tube is completely filled, gently invert the sample tube at least five times to ensure complete mixing of the contents.
UCMC Offsite and UC MedLab Outreach Instructions:
- Collect specimen per standard collection procedure.
- Once each blue top tube is completely filled, gently invert the sample tube at least five times to ensure complete mixing of the contents.
- 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 |
TT, heparin removed |
ALL |
ALL |
18.5 - 22.3 seconds |
Critical Values
Analyte |
Unit |
Low |
High |
Age |
N/A |
N/A |
N/A |
N/A |
N/A |
CPT Codes
85670, 85525
LOINC Codes
3243-3
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.
NOTE: Once each blue top tube is completely filled, gently invert the sample tube at least five times to ensure complete mixing of the contents.
Test Components
Thrombin Time (TT) post heparin removal.
Clinical Indications
Measuring thrombin time after heparin removal.
Detecting or excluding the presence of heparin or direct thrombin inhibitors.
Methodology
Clotting
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: 8 hours
Testing Schedule: 7 days a week. 8 am to 10:30 pm
Synonyms/Keyword Search
Hepzyme TT; Hepcheck TT
Last Review Date
06/06/2024