Specimen Requirements

Container/Tube Type: 

Light Blue (Citrate)

Collection Information: 

Tube must be filled to a 1:9 ratio- see tube label for proper amount of blood

Transport Information: 

2.7 mL blood in a 3.0 mL tube (min: 1.8 mL blood in a 2.0 mL tube)

Remarks: 

3.2% buffered sodium citrate is the only acceptable anticoagulant concentration for this testing. Care should be taken to invert the tube several times immediately after collection to prevent clotting. Tube should be centrifuged as soon as possible and the plasma separated from the cells.

Unacceptable Conditions: 

Clotted, Hemolyzed, improperly filled tubes resulting in other than a 1:9 ratio of blood to anticoagulant

Stability Comments:

Platelet Poor Plasma
Centrifuge Specimen
Recommended centrifuge speed is 1500 x G for at least 15 minutes or 5100 x G for 5 minutes.. Be careful that the tubes are evenly balanced when placing them into the centrifuge. When the centrifuge stops, carefully remove and rack tubes. Be aware that an unbalanced centrifugation, speed too slow, or centrifugation for too short of a spin time may all lead to an increase number of cells in the plasma which could contribute to a clotted specimen or erroneous results.
Remove Plasma
To remove plasma, start from the top, gently draw specimen into pipette as you go further down tube. Leaving approximately 0.5mL of plasma will insure that you do not disturb the buffy coat and cell layer.
Second Spin
Plasma separated from cells goes back into the centrifuge for a second spin. Balance and centrifuge the tubes. Failure to perform a second spin will result in plasma containing too many platelets which interfere with some coagulation testing and is a contributing factor for a clotted specimen.
 

Transfer Plasma to Aliquot Tubes
Pipette plasma from second spin tube into labeled aliquot tubes without disturbing the bottom 0.5mL.
 

Specimen Storage
Promptly freeze specimens after processing.