Specimen Requirements

Specimen must be tested within 4 hours of draw.

Collect therapeutic range samples 4-6 hours after subcutaneous injection.  

Due to specimen stability requirements, outpatients should be drawn at Munson Medical Center Outpatient Laboratory.  When a sample must be drawn at another location, call the hospital laboratory prior to collection to confirm specimen transportation arrangements will meet specimen stability adn 4-hour testing requirements, and label specimen for priority testing.

Container/Tube: Light blue top (sodium citrate) tube

Specimen Volume: 4.5 mL (pediatric: 2.7 mL) sodium citrate whole blood

Transport Temperature:  Ambient only.

Collection Instructions:  Do not centrifuge. Do not refrigerate. Deliver to the laboratory immediately.

Special Instructions: 

1. If a specimen cannot be tested within 4 hours of draw, plasma should be removed from the cells and preserved as follows: Spin in a centrifuge verified for platelet-poor plasma preparation, remove plasma to a plastic tube, spin the plasma a second time, then remove plasma to a screw-top plastic  tube and freeze immediately at -20° C. Transport frozen. 

2. For difficult to draw patients less than 1 year old: Proper blood/anticoagulant ratio is required for accurate testing.  Special tubes with a decreased amount of anticoagulant may be prepared by the Hematology lab to allow for a smaller amount of blood collection.  Call the Hematology lab at 935-6118 to request preparation of a "modified" pediatric sodium citrate blue top tube that allows for reduced volume of blood sample..

3. Line draws: A physician's order is required for line draws for coagulation testing. Single lumen draws are acceptable if the port does not have heparin or a heparin flush solution.  Double lumen lines can be used if the heparin-free lumen is accessed, even when the other lumen contains a heparin flush sollution.