Test Catalog

Test ID: F11IS    
Coagulation Factor XI Inhibitor Screen, Plasma

Useful For Suggests clinical disorders or settings where the test may be helpful

Detection and quantitation of inhibitor to coagulation factor XI


This test is not useful for detecting a nonspecific circulating anticoagulant or the presence of inhibitors directed against other clotting factors.


This test is not useful for the detection of lupus anticoagulants.

Profile Information A profile is a group of laboratory tests that are ordered and performed together under a single Mayo Test ID. Profile information lists the test performed, inclusive of the test fee, when a profile is ordered and includes reporting names and individual availability.

Test IDReporting NameAvailable SeparatelyAlways Performed
F_11Coag Factor XI Assay, PYesYes
11_ISFactor XI Inhib ScrnNoYes

Reflex Tests Lists tests that may or may not be performed, at an additional charge, depending on the result and interpretation of the initial tests.

Test IDReporting NameAvailable SeparatelyAlways Performed
IBETHBethesda UnitsNoNo
CCCRSpecial Coagulation InterpretationNoNo

Testing Algorithm Delineates situations when tests are added to the initial order. This includes reflex and additional tests.

Testing begins with coagulation factor XI activity assay with dilutions to evaluate assay inhibition; if the factor XI activity assay is normal or increased, the inhibitor screen will be cancelled. If the factor XI activity assay is decreased, an inhibitor screen will be performed to look for specific factor XI inhibition. If specific inhibition is apparent, the titer of the inhibitor will be determined.

Special Instructions Library of PDFs including pertinent information and forms related to the test

Method Name A short description of the method used to perform the test

Optical Clot-Based

NY State Available Indicates the status of NY State approval and if the test is orderable for NY State clients.


Reporting Name Lists a shorter or abbreviated version of the Published Name for a test

Coag Factor XI Inhibitor Scrn, P

Aliases Lists additional common names for a test, as an aid in searching

Factor XI Inhibitor Screen, Plasma