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Factor 10 Activity, Chromogenic

Item Value
Approval req'd? No
Available Stat? No
Test code FXCH
Performed by Quest
Sendout? Yes
Method Chromogenic
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 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UCSF Rejection Criteria Samples collected in outdated blue top vacutainer.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 Deliver sample to Hematology ASAP for processing.

Separate platelet poor plasma. Freeze at least 1 mL of plasma in a plastic tube at -20C. Order Quest test# 10663X

Ship Monday-Thursday on dry ice to Send-outs at China Basin for processing to forward to Quest.

NOTE: For Brown and Toland patients (BTMOLT), ship the frozen plasma to LabCorp, test code 821728.
Units % activity
Normal range
Normal 73-158% activity
Therapeutic range for patients on coumadin 11-42%
Synonyms F10; FX; Factor X chromogenic
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 Test run 6 x per week. Turnaround 3-5 days.
Additional information Useful in regulating coumadin therapy in a patient with a lupus anticoagulant, which occasionally interferes with PT assays.

A prothrombin time (PT) and Factor X Chromogenic should be ordered on the same specimen when a Factor X Chromogenic is requested. If the INR is <1.5, the Factor X Chromogenic will be cancelled.
CPT coding 85260-90
LOINC code 33984-6
Last Updated 1/29/2015 4:22:07 PM
Entry Number 366
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