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HelpTest Code F VII Factor VII Assay
Useful For
Coagulation factors are necessary for the normal functions of the extrinsic and intrinsic coagulation systems. A deficiency of any of the factors will limit the function of the coagulation cascade. Protime (PT) based assays will be used for factors of the extrinsic coagulation system (V, VII) and the PTT for the intrinsic coagulation system (VIII, IX).
Patient Preparation
No special patient preparation required
Special Collection Instructions
Properly filled 9:1 ratio (blood to anticoagulant); 3.2% NaCitrate tubes
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
50-129%
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, hemolyzed, lipemic or icteric samples, 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) | 2 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 - Photo-optical clot-detection system |
Additional Information/Important Notes
After being spun down twice, separate plasma into 2 aliquot tubes and transport to University Hospital Laboratory frozen on dry ice.
CPT Codes
85230
Special Handling
Centrifugation: 5 minutes at 5000 rpm. Plasma must be centrifuged twice
(double spun) to remove platelets. (<10,000 mm3)