|Light Blue top tube 1.8 mL (Na Citrate)
Full draw; 1.8 mL light blue top (mix well). Tube must be at least 90%
Short drawn tube, clot, traumatic tap (excessive hemolysis).
1 hour (upon receipt in laboratory)
INR Critical Reference Value: greater than 3.9
The INR corresponding to the PT is reported to assist in the
monitoring of oral anticoagulants. Must be drawn swiftly with a clean
venipuncture (no hematoma). Time drawn must be indicated on
requisition. A PT can be performed on a sample if it is kept unopened
and uncentrifuged at room temperature to be delivered to lab within 24
hours. A special tube from the lab is necessary if the hematocrit is
Prothrombin Time may be performed on the same collection tube as
Activated Partial Thromboplastin time (aPTT) and Fibrinogen.
This test is also performed in the Iowa
River Landing (IRL) clinical laboratory (for specimens drawn at that
Optical clot detection.