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HelpTest Code Prot S Protein S, Free
Useful For
Protien S is synthesized in the liver as an inactive precursor. The active form is obtained after carboxylation of glutamic residues by a Vitamin K- dependent carboxylase. Protien S greatly enhances the anticoagulant functin of activated Protein C, probably by increasing Protein C affinity for phospholipid membranes. Total and free Protein S levels are higher in men than women and increase with age. Acquired Protein S Deficiency occurs in many clinical disorders:
1. Liver Disease ? Hepatitis, Cirrhosis
2. Disseminated Intravascular Coagulation
3. L-asparaginase treatment
4. Inflammatory Syndrome
Patient Preparation
No special patient preparation required
Special Collection Instructions
Properly filled 9:1 ratio (blood to anticoagulant); 3.2% NaCitrate tube
Collection Method
Venous Draw; properly filled 9:1 ratio (blood to anticoagulant)
Minimum Volume
0.5 ml of plasma from a properly filled 1.8 mL or 2.7 mL NaCitrate (light blue) tube
Container
Light Blue Sodium Citrate
Preferred Specimen
2.7mL Lt. Blue (3.2% NaCitrate)
Acceptable Specimens
1.8 mL Lt. Blue (3.2% NaCitrate) tube
Reference or Target Ranges
Normal Male Range: 74.1 - 146.1%
Normal Female Range: 54.7 - 123.7%
Reportable Units
% (percentage)
Critical Value
Not defined for this assay
Reasons for Rejection
| Hemolysis Threshold | N/A |
| Icterus Threshold | N/A |
| Lipemia Threshold | N/A |
| Interfering Subtances/Other | Short draws, over draws, clotted, improperly labeled, samples >4 hours from collection |
Specimen Stability
| Ambient | Plasma – 4 hours |
| Refrigerated (4°C to 8°C) | N/A |
| Frozen(-70°C to -20°C) | 4 weeks@ -20°C; 1 year @ -70°C |
Performance Information
| Days and Time Performed | Batched weekly Monday-Friday |
| Expected Turn Around Time | Batched Monday – Friday |
| Stat Availability | No |
| Performing Bench | Coagulation |
| Methodology/Method Description | Werfen ACL TOPS - Latex Ligand Immunoassay |
Additional Information/Important Notes
After being spun down, separated plasma must be transported to University Hospital Laboratory frozen on dry ice.
CPT Codes
85306
Special Handling
Centrifugation: 5 minutes at 5000 rpm. Plasma must be centrifuged twice
(double spun) to remove platelets. (<10,000 mm3)