Specimen Requirements

Preferred Collection Container: 

Light Green (Lithium Heparin Plasma Separator Tube) - ON ICE
Green No Gel (Lithium Heparin) - ON ICE

Also Acceptable Collection Container: 

SST (Serum Separator) - ON ICE
Red (No Additive) - ON ICE
Plasma from Lavender tubes is acceptable but will not route in the Laboratory Information System (Sunquest) - ON ICE

Collection Information: 

Place tube on ice immediately after collection. Collect a Light Green (Lithium Heparin Plasma Separator Tube) or Green No Gel (Lithium Heparin). SST (Serum Separator), Red (No Additive), and Lavender (EDTA) also acceptable.

Transport Information: 

Centrifuge and aliquot 1.0 mL plasma or serum into a plastic transport vial. Send refrigerated.

Minimum Sample Volume: 

0.2 mL of plasma or serum (Approximately 0.5 mL of whole blood based upon a normal patient hematocrit).

Remarks: 

Plasma or serum must be separated from cells within 1 hour of collection. Sample should be stored on ice while awaiting centrifugation. Specimens not placed on ice may exhibit a 10-20% increase in homocysteine concentration.

Do not use serum and plasma interchangeably from the same patient.

Unacceptable Conditions: 

Whole blood samples not transported on ice.
Whole blood samples not separated from cells within one hour.
Grossly hemolyzed specimens.

Stability Comments: 

Stability limits apply after separation from cells.