PT - Specimen: Prothrombin Time, Plasma

Test Catalog

Test ID: PT    
Prothrombin Time, Plasma

Specimen Type Describes the specimen type needed for testing

Plasma Na Cit

Specimen Required Defines the optimal specimen. This field describes the type of specimen required to perform the test and the preferred volume to complete testing. The volume allows automated processing, fastest throughput and, when indicated, repeat or reflex testing.

Platelet-Poor Plasma

Collection Container/Tube: Light-blue top (3.2% sodium citrate)

Submission Container/Tube: Plastic vial

Specimen Volume: 0.5 mL

Specimen Stability Information: Frozen

Collection Instructions: Spin down, remove plasma and spin plasma again

Additional Information: Double-centrifuged specimen is critical for accurate results as platelet contamination may cause spurious results.


Whole Blood (Available to local accounts only)

Container/Tube: Light-blue top (3.2% sodium citrate)

Specimen Volume: 4.5 mL

Specimen Stability Information: Ambient

Collection Instructions: Protime must be completed within 24 hours of draw time.

Specimen Minimum Volume Defines the amount of specimen required to perform an assay once, including instrument and container dead space. Submitting the minimum specimen volume makes it impossible to repeat the test or perform confirmatory or perform reflex testing. In some situations, a minimum specimen volume may result in a QNS (quantity not sufficient) result, requiring a second specimen to be collected.

Whole blood: 1.8 mL/Plasma: 0.5 mL

Reject Due To Identifies specimen types and conditions that may cause the specimen to be rejected










Specimen Stability Information Provides a description of the temperatures required to transport a specimen to the laboratory. Alternate acceptable temperature(s) are also included.

Specimen TypeTemperatureTime
Plasma Na CitFrozen (preferred)30 days
 Ambient 24 hours