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22446 Factor Assay-10 (X)

Factor Assay-10 (X)
Test Code: F-X
Synonyms/Keywords
​Factor X Activity, Factor X Clotting
Useful For
​This test is used to identify Factor X deficiency only.
To monitor warfarin therapy, order Chromogenic Factor X (CHX).
To monitor low molecular weight heparin (Lovenox, etc.), order Low Molecular Weight Heparin (HEPLMW).
To monitor unfractionated heparin, order Heparin, Unfractionated (HEPUF).
To monitor fondaparinux (Arixtra), order Fondaparinux (ARIXTRA).
Specimen Requirements
Specimen Type Preferred Container/Tube Acceptable Container/Tube Specimen Volume Specimen Minimum Volume
(allows for 1 repeat)		 Pediatric Minimum Volume
(no repeat)
*Platelet Poor Plasma 3.2% Citrated Blue Top Tube (BTT)​ ​ 0.75 mL ​ 0.75 mL ​ 0.5 mL​
Collection Processing Instructions
​One 0.75 mL citrated Blue Top Tube (BTT) plasma aliquot.
If more than one coagulation test is ordered, a separate aliquot is needed for each test.
-Collect in Citrated Blue Top Tube (BTT)
-Citrate anticoagulant must be adjusted for HCT >55%
-Tube must be at least 90% full
-Invert completely 3-4 times (without shaking) to mix
*See Instructions for: Preparation of Platelet Poor Plasma
Specimen Stability Information
Specimen Type Temperature Time
​Plasma ​Frozen ​6 months
Rejection Criteria
Clotted or Hemolyzed
Contamination with IV or Hickman Line fluids
​Specimens that thaw during storage or transport
Performing Laboratory Information
Performing Location Day(s) Test Performed Analytical Time Methodology/Instrumentation
​Marshfield ​Monday through Friday ​Less than 2 hours Modified PT substitution/optical clot detection/Siemens BCSXP​
Reference Range Information
Performing Location Reference Range
​Marshfield 65-165%​
Outreach CPTs
CPT Modifier
(if needed)		 Quantity Description Comments
​85260 ​ ​ ​
Synonyms/Keywords
​Factor X Activity, Factor X Clotting
Ordering Applications
Ordering Application Description
​Centricity ​Factor-X
​Cerner Factor X Assay
​COM ​Factor Assay-10 (X)
If the ordering application you are looking for is not listed, contact your local laboratory for assistance.
Specimen Requirements
Specimen Type Preferred Container/Tube Acceptable Container/Tube Specimen Volume Specimen Minimum Volume
(allows for 1 repeat)		 Pediatric Minimum Volume
(no repeat)
*Platelet Poor Plasma 3.2% Citrated Blue Top Tube (BTT)​ ​ 0.75 mL ​ 0.75 mL ​ 0.5 mL​
Collection Processing
​One 0.75 mL citrated Blue Top Tube (BTT) plasma aliquot.
If more than one coagulation test is ordered, a separate aliquot is needed for each test.
-Collect in Citrated Blue Top Tube (BTT)
-Citrate anticoagulant must be adjusted for HCT >55%
-Tube must be at least 90% full
-Invert completely 3-4 times (without shaking) to mix
*See Instructions for: Preparation of Platelet Poor Plasma
Specimen Stability Information
Specimen Type Temperature Time
​Plasma ​Frozen ​6 months
Rejection Criteria
Clotted or Hemolyzed
Contamination with IV or Hickman Line fluids
​Specimens that thaw during storage or transport
Useful For
​This test is used to identify Factor X deficiency only.
To monitor warfarin therapy, order Chromogenic Factor X (CHX).
To monitor low molecular weight heparin (Lovenox, etc.), order Low Molecular Weight Heparin (HEPLMW).
To monitor unfractionated heparin, order Heparin, Unfractionated (HEPUF).
To monitor fondaparinux (Arixtra), order Fondaparinux (ARIXTRA).
Reference Range Information
Performing Location Reference Range
​Marshfield 65-165%​
For more information visit:
Performing Laboratory Information
Performing Location Day(s) Test Performed Analytical Time Methodology/Instrumentation
​Marshfield ​Monday through Friday ​Less than 2 hours Modified PT substitution/optical clot detection/Siemens BCSXP​
For billing questions, see Contacts
Outreach CPTs
CPT Modifier
(if needed)		 Quantity Description Comments
​85260 ​ ​ ​
For most current information refer to the Marshfield Laboratory online reference manual.