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Laboratory Medicine

Test catalogue


Test Name


Blue top Specimen Type / Requirements

Container Type = Blue Tube (Sodium Citrate)

Minimum Volume = Full draw

9:1 Ratio (9 parts blood to 1 part anticoagulant)

Specimen Handling

Collection Instructions: Must indicate anticoagulant status to avoid delay.

Write your initials, date and time of collection on the collection label.

Transportation: In/Outpatients: Send whole citrated blood at room temperature as soon as possible. Referred-in: Send frozen citrated plasma on dry ice. All samples must be sent to the Core Laboratory.

Stability: Specimens are stable for 4 hours post collection at room temperature. Specimens which are not tested within 4 hours can be double-spun to remove the citrated plasma. The citrated plasma is stable at -20°C for up to two weeks or -70°C for up to six months.

Sample Rejection Criteria: Clotted sample, grossly hemolyzed samples, Unlabeled or samples with insufficient quantity will be rejected.

Required Documentation

Turnaround Time (TAT)



Test Utilization

Reference Value


PT: 10.0 - 13.0 seconds

INR: 0.90 - 1.20

Pediatric (< 3 months):

PT: 10.8 - 15.5 seconds

INR: = 0.90 - 1.60

Critical Values

INR: 5.00

Test Code



Clotting Assay

Testing Location

SMH-Routine Coagulation

Other Information

Last Updated: June 06, 2019