Specimen Requirements
Collection Instructions
Collect specimen in a blue top (citrate 3.2%) tube. Mix by inversion. Specimen should arrive at lab within one hour of collection; transport at room temperature. Alternatively, centrifuge, aliquot plasma into a plastic vial, and freeze the specimen within 1 hour of collection. Transport frozen specimen on dry ice. Collection of the blood through lines that have been previously flushed with heparin should be avoided. If the blood must be drawn through a VAD (vascular access device), the line should be flushed with 5 mL of saline and the first 5 mL of blood or six dead space volumes of the VAD discarded.
Special Handling
Specimen must be received in lab within one hour of collection. Alternatively, aliquot and freeze within 1 hour of collection.
Rejection Criteria
Specimens will be rejected if not properly filled, clotted, grossly hemolyzed, contaminated with heparin, or received outside acceptable time limits.
Contraindications
Test is not indicated if the patient is receiving low molecular weight heparin or any other Anti-Xa drug.
Normal Volume
Full 2.7mL tube or 1mL plasma aliquot
Minimum Volume
Full 1.8mL tube or 1mL plasma aliquot
Storage Temperature
Room temperature for whole blood or frozen aliquot of citrated plasma