Mixing Study: Specimen Requirements
The specimen drawn for a mixing study must meet the following conditions for accurate testing:
- A properly filled 3.2% sodium citrate tube must be collected.
- Proper centrifugation to create platelet-poor plasma for analysis must occur; the presence of platelet phospholipids can interfere with the mixing study if an anti-phospholipid antibody is present.
- Testing must be performed within 4 hours of collection.
 http://www.ncnr.nist.gov/userlab/e134.html |  Properly Filled Sodium Citrate Tube |