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Factor 12 Activity

Item Value
Approval req'd? No
Available Stat? No
Test code F12A
Test group Coagulation Factor Activities
Performed by UC Davis
Sendout? Yes
Method Photometric clot detection
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: 3-1747, Mission Bay: call 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 1.5 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UCSF Rejection Criteria Samples collected in outdated blue top vacutainer.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. Centrifuge and freeze platelet poor plasma at -20C.

For B&T patients order Labcorp test #086322
Units %
Normal range Age
Newborn - Day 4 13-93%
Day 5 - 1 Month 11-83%
1 Month - 3 Months 17-81%
3 Months - 6 Months 25-109%
6 Months - 1 Year 39-115%
1 Year - 5 Years 64-129%
6 Years - 10 years 60-140%
11 Years - 16 Years 34-137%
≥ 17 Years 50-150%
Synonyms F12; FXII; Factor XII; Contact factor; Contact activation factor
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 Performed 5x per week. Turnaround 3-5 days.
Additional information Factor 12 Deficiency is not associated with a bleeding diathesis.
CPT coding 85280-90
LOINC code 3232-6
Last Updated 6/24/2016 12:23:43
Entry Number 368
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