Collection/Processing Instructions

This test requires three samples:
1. 1.0 mL 3.2% citrated plasma - blue top tube, (BTT) used for PT, APTT, and FIB.

2. 1.0 mL 3.2% citrated platelet poor plasma - blue top tube, (BTT) used for D-dimer.
3. 2.0 mL EDTA whole blood - lavender top tube, (LTT) used for platelet determination.
 

Minimum volume:
1. 1.0 mL 3.2% citrated plasma - blue top tube, (BTT)
2. 0.5 mL 3.2% citrated platelet poor plasma - blue top tube, (BTT)

3. 1.0 mL EDTA whole blood - lavender top tube, (LTT) and 2 unfixed smears 

Processing Instructions:

Blue top tubes:

• Must be drawn to the fill line.
• Invert tubes completely 3-4 times to mix.
• Do not shake.  

First blue top tube:

• Centrifuge at 3000 rpm for 10 minutes with the brake OFF as soon as possible after collection.
• Perform testing within one hour of sample collection or separate citrated plasma for storage.
• Use plastic pipette to transfer top half of plasma to polypropylene tube.
• Avoid platelet contamination.
• Cap tightly.    

Second blue top tube:

• See "Preparation of Platelet Poor Plasma"    

EDTA lavender top tube:

• Test should be performed within 24 hours of collection.
• If not performed within 4 hours of collection, two smears should be prepared immediately for use in confirming abnormal counts.