Buffy Coat Processing
Acceptable Tube Types
If you plan to extract nucleic acids from materials, Purple-top and
Yellow-top tubes are most commonly used.
- Purple top tube (EDTA anti-coagulant). Commonly 4.0 or 10mL
volume tubes for collection of whole blood.
- Green top tube (lithium heparin anti-coagulant). Commonly
4.0, 5.0 or 10mL tube. Note the heparin anti-coagulant
interferes with many nucleic acid extraction protocols
- Blue top tube (sodium citrate anti-coagulant. Commonly
3.0, 5.0 or 10mL tubes for collection of whole blood. Used primarily
for coagulation testing.
- Yellow top tube (ACD, acid-citrate-dextrose anti-coagulant).
Uncommon sample, but often received as 10mL tube.
Variations (added per request to study protocol).
- Spin at 3000rpm for 10 minutes at room temperature (25*C).
- Use a sterile pipette to pull off plasma, leaving no more
than 0.5mL of plasma over the cell interface.
- Note the buffy coat/yellowish layer over the packed RBC layer.
- With a single-use pipette, collect as much of the yellow
layer as possible (generally in <0.5mL volume), avoiding taking
significant amounts of plasma or RBCs.
- Transfer the buffy coat to a sterile pour-off tube or
- Spin time: Can be modified from 10 minutes.
- Spin temperature: Can be modified from 25*C (4*C-42*C).
- Storage conditions: ambient, 4*C, -20*C, -80*C.
- Alternate collection tube, including:
- Eppendorf tubes: 1.8mL, 2.0mL.
- Screw capped tubes: 2.0mL, 10mL.
- Cryovials: specify volume, size (1", 2").