Specimen Requirements

Preferred Collection Container: 

Green (Lithium Heparin)
Light Green (Heparin Plasma Separator Tube)

Also Acceptable Collection Container: 

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

Collection Information: 

Place tube on ice immediately after collection. Collect a Green lithium heparin tube (preferred). Also acceptable are a Serum (red) or EDTA (lavender) top tube.

Transport Information: 

1 mL plasma or serum on ice.

Plasma or serum separated from cells: Ambient: 4 days; Refrigerated: 4 weeks; Frozen: 10 months

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.