Test Name
PT/ INR
Aliases
PROTHROMBIN TIME/ INTERNATIONAL NORMALIZED RATIO
Abbreviations
PT
Test Classification
GROUPED TEST
Department
HEMATOLOGY
Sub Department
COAGULATION
TAT Category
BUSINESS (WORKING) TIME
Estimated TAT
2
TAT Units
HOURS
Test Requirements
Collect whole blood in CITRATE TUBE (LIGHT BLUE CAP) FILLED UP TO THE MARK & submit to the lab immediately at ROOM temperature. If >24 hour delay is expected between collection & analysis, centrifuge, separate plasma & freeze. Submit frozen plasma. Provide history e.g. whether patient is on anticoagulants (e.g. warfarin) and whether they have a bleeding tendency.
Test components: Prothrombin time, INR
SHIPPING/ TRANSPORTATION REQUIREMENTS
Shipping Temperature: Refrigerated
ANALYTE STABILITY
Room Temperature: 2-8 hours at 20-25°C │ Refrigerated: 2-8 hours at 2-8°C │ Frozen: 2 WEEKS at -20°C
Clinical Utility
Monitor patients on warfarin therapy. Examine factor deficiency in the extrinsic & common coagulation cascade pathway. Evaluate patients with bleeding disorders and liver disease.
Last Review
26th Feb 2026