Thrombin Time
| Label Mnemonic: | TT |
| Epic code: | LAB324 |
| Order form: | Laboratory Requisition |
| Supply order: | Supply Order Form |
| Billing: | Billing Policies |
| CPT code: | 85670 |
Specimen(s):
Plasma More information
Collection Medium:
 |
| Light Blue top tube 1.8 mL (Na Citrate) |
Minimum:
Full draw; 1.8 mL light blue top (mix well). Tube must be at least 90% full.
Rejection Criteria:
Short drawn tube, clot, traumatic tap (excessive hemolysis).
Testing
Schedule:
24 hrs/day, 7 days a week, including holidays.
Turn Around
Time:
3 hours (upon receipt in laboratory)
Reference Range:
17-20 seconds
Reference range updated on 12/16/2019 due to new assay reagent.
Methodology:
Optical clot detection.
Sample
Processing:
Double-centrifuge specimen to prepare platelet-free plasma.
Immediately centrifuge specimen at 3500 RPM for 12 minutes.
Using a plastic transfer pipette, carefully remove plasma from cells avoiding the platelet/buffy coat.
Place plasma into a labeled plastic tube.
Centrifuge plasma again at 3500 RPM for 12 minutes.
Remove the top of the plasma and place into a labeled plastic tube.
Freeze double-spun plasma within 4 hours of collection time at -20 degrees C or below.
Immediately centrifuge specimen at 3500 RPM for 12 minutes.
Using a plastic transfer pipette, carefully remove plasma from cells avoiding the platelet/buffy coat.
Place plasma into a labeled plastic tube.
Centrifuge plasma again at 3500 RPM for 12 minutes.
Remove the top of the plasma and place into a labeled plastic tube.
Freeze double-spun plasma within 4 hours of collection time at -20 degrees C or below.
Sample
Storage:
Freeze plasma immediately.
Transport
Instructions:
Place labeled specimen into zip-lock type biohazard bag; seal bag.
Place requisition into outside pocket of bag.
Place dry ice on top of specimen in Styrofoam container to maintain frozen temperature.
Samples received thawed will be cancelled.
Place requisition into outside pocket of bag.
Place dry ice on top of specimen in Styrofoam container to maintain frozen temperature.
Samples received thawed will be cancelled.
See Additional Information:
Phlebotomy Tubes and Order of Draw
Hemolysis Chart
Impact of Common Anticoagulants on Coagulation Tests
Phlebotomy Tubes and Order of Draw
Hemolysis Chart
Impact of Common Anticoagulants on Coagulation Tests