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Test ID PTTP Prothrombin Time, Plasma

Useful For

Screening assay to detect deficiencies of one or more coagulation factors (factors I, II, V, VII, X)


Screening assay to detect coagulation inhibition


Monitoring intensity of oral anticoagulant therapy when combined with INR reporting

Method Name

Coagulometric (Turbidimetric)

Reporting Name

Prothrombin Time, P

Specimen Type

Plasma Na Cit

Specimen Required

Specimen Type: Platelet-poor plasma

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

Submission Container/Tube: Plastic vial

Specimen Volume: 1 mL

Collection Instructions:

1. Centrifuge, remove plasma, and centrifuge plasma again.

2. Aliquot plasma into plastic vial leaving 0.25 mL in the bottom of centrifuged vial.

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

Specimen Minimum Volume

0.5 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Plasma Na Cit Frozen (preferred) 30 days
  Ambient  24 hours

Reference Values


9.4-12.5 seconds





Standard intensity warfarin therapeutic range: 2.0-3.0

High intensity warfarin therapeutic range: 2.5-3.5

Day(s) Performed

Monday through Sunday

Report Available

Same day/1 day

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Test Classification

This test has been cleared, approved, or is exempt by the US Food and Drug Administration and is used per manufacturer's instructions. Performance characteristics were verified by Mayo Clinic in a manner consistent with CLIA requirements.

CPT Code Information


LOINC Code Information

Test ID Test Order Name Order LOINC Value
PTTP Prothrombin Time, P 34528-0


Result ID Test Result Name Result LOINC Value
PTTTP Prothrombin Time, P 5902-2
INRTP INR 6301-6

NY State Approved