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Factor 8 Activity
|Clinical Questions||Does my patient have von Willebrand disease? If so, which type?|
|Test group||Coagulation Factor Activities|
|Performed by||Parnassus & Mission Bay Hematology|
|In House Availability||Test run 0800-1500 Monday-Friday.
Note: If testing is needed outside of these hours, contact Hematology. For Parnassus patients call 3-1747, for Mission Bay patients call 6-0194.
|Method||Clotting assay (Stago - STAR)|
|Collection Instructions||1. Check the expiration date on the label of the blue top vacutainer before drawing the patient.
2. For blood collection in a sodium citrate blue top, the tube must be filled to above the Minimum Fill Indicator on the tube. It is crucial to wait and allow the tube to stop filling before removing it from the needle.
3. With use of a butterfly needle, draw about 1 cc using a separate blue top to remove air from tubing, discard the first tube and then draw a second blue top tube filled to the full extent of the vacuum.
4. Tubes should not be filled past the Maximum Fill dashed line by either using a syringe or removing the tube cap.
Deliver immediately to the laboratory.
For patients with Hct's ≥ 55% please contact Hematology (Parnassus: x3-1747, Mission Bay 6-0194) to obtain blue top tubes with adjusted citrate volumes in order to maintain the proper citrate to plasma ratio for coagulation studies.
|Container type||Blue top filled to full extent of vacuum|
|Amount to Collect||2.7 mL blood|
|Sample type||Citrated plasma|
|Preferred volume||1 mL plasma|
|Min. Volume||0.5 mL plasma|
|UCSF Rejection Criteria||Samples collected in outdated blue top vacutainer. Over-filled or under-filled tubes may be rejected|
|Processing notes||Provide sample(s) to Hematology section asap.|
Note: During infancy, Factor VIII values can be greater than those observed in adults. Nevertheless, a value of approximately 50% was noted as the lower limit of normal for full term infants from birth to 6 months. (Reference: Andrew M. et al. Blood 1987 70:165).
|Synonyms||F8; FVIII; FVIII:C; Factor VIII|
|Stability||Factor assays should generally be performed within four hours of specimen collection or the plasma frozen; the latter is stable for 2 weeks at -20C or 6 months at -70C.|
|Turn around times||1-3 days|
|Additional information||If unusual findings are noted a pathologist review and interpretation may be performed and separately billed for|
|Last Updated||1/29/2015 4:19:39 PM|