Room temperature samples Refrigerated samples Clotted samples Samples submitted in inappropriate anticoagulant
Reference Range(s)
Age and gender specific normals. Will reflex to Protein S Antigen free and Protein S Antigen Total when result is below reference range. Additional charges will apply
Specimen Requirements
Preferred Specimen
Sodium Citrate Light Blue Top Tube
Minimum Volume
2 aliquots of 1 mL frozen plasma each
Sample Stability
4 hours room temperature Unacceptable refrigerated 1 month frozen at -20 degrees C
Transport Temperature
Critical Frozen
Collection Instructions
1. This test requires 2 frozen plasma aliquots. Fill 2 light blue top tubes as far as vacuum will allow and mix by gentle inversion five to six times. The exact ratio of 1 part sodium citrate to 9 parts blood must be maintained. Inadequate filling of the tubes will alter this ratio and may lead to inaccurate results. 2. Patients who have hematocrit values above 55% should have the anticoagulant adjusted to maintain the 1 to 9 ratio. 3. To obtain platelet-poor plasma, immediately centrifuge samples at 1500 RCFs for 15 minutes, then pipette the supernatant plasma and transfer to 2 plastic transport tubes. 4. Re-centrifuge plasma in the plastic transport tubes at 1500 RCFs for 15 minutes to ensure that no red cells are present. 5. Pipette the top two-thirds of the supernatant plasma and divide all plasma evenly and transfer to 2 separate plastic transport tubes. Clearly label tubes as citrate plasma. 6. Immediately freeze the plasma at -20 degrees C or lower for transport. 7. When multiple tests are ordered, submit separate tubes for this test. Patient prep: patients should discontinue oral anticoagulant therapy for at least 2 weeks prior to testing, upon the advice of their physician.