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Thrombin Time (TT)

Mnemonic:    [THROMBIN]
Name:    Thrombin Time (TT)
Specimen:    2 mL plasma from a FULL sodium citrate Blue top tube. Allow tube to fill to proper capacity. Mix immediately by gentle inversion 4 times.
Room temperature sample must be delivered to the CMMC hematology lab within one hour of collection. If the unspun sample cannot be delivered to the lab in that time period, the patient should be sent to the CMMC Outpatient Phlebotomy area for specimen collection.

Specimen storage from the time of collection:
--If the patient is on heparin therapy, the specimen is stable at room temperature for 2 hours.
--If the patient is not on heparin and the sample has not been uncapped, the specimen is stable for 8 hours.
--If the patient is not on heparin and the sample has been uncapped for previous testing, the specimen is stable for 4 hours.
--Plasma samples can be frozen and thawed once.

Unacceptable Specimens: tubes that are overfilled or underfilled, clotted or hemolyzed.
Reference Range:    14.4 - 21.0 seconds
  Method:    Mechanical Clot Detection
Note:    Note if patient is on heparin or coumadin.
Processing Info:    The sample must be kept at room temperature prior to centrifugation. Any samples received separated must have been processed in a CAP approved calibrated and documented centrifuge to provide platelet poor plasma.