Specimen Requirements

Specimen Type: Plasma or serum

Container/Tube:

Plasma: Lithium heparin (plain or gel separator), sodium heparin, potassium EDTA, or sodium EDTA

Serum: Clot, plain, activator, or gel separator

Specimen Volume: 0.5 mL

Specimen Minimum Volume: 0.2 mL

Collection Instructions: Preferred sample time for monitoring is before the next dose (trough).

Additional Information:

*Heterophilic antibodies in human serum can react with reagent immunoglobulins, interfering with the assay.

Note:  If testing delayed for more than 48 hours, remove serum or plasma from the clot, red blood cells, or separator gel.