Bethesda Titer
9 days
The factor XI inhibitor (Bethesda Titer) assay is performed using an activated partial thromboplastin time (aPTT)-based test system.
Test Includes: Activated partial thromboplastin time (aPTT), aPTT 1:1 mix with normal plasma, aPTT 1:1 mix with saline, factor XI activity, factor XI Bethesda titer
Accredited Laboratory Partner
Contact Technical Support
Evaluates for the presence of inhibitors (autoantibodies) against Factor XI. Used in patients with acquired Factor XI deficiency, unexplained prolonged aPTT, or bleeding despite normal antigen levels. Helps differentiate between inherited and acquired causes of bleeding.
Plasma
6 mL (2 mL in each of 3 tubes)
Blue top (sodium citrate) tube
No special preparation is required for this test. You may eat, drink, and take your medications as normal, unless instructed otherwise by your healthcare provider.
Citrated Plasma samples should be collected by double centrifugation
| Temperature | Period |
|---|---|
| Frozen | Contact Technical Support |
Bethesda Titer
9 days
The factor XI inhibitor (Bethesda Titer) assay is performed using an activated partial thromboplastin time (aPTT)-based test system.
Test Includes: Activated partial thromboplastin time (aPTT), aPTT 1:1 mix with normal plasma, aPTT 1:1 mix with saline, factor XI activity, factor XI Bethesda titer
Accredited Laboratory Partner
Contact Technical Support
Evaluates for the presence of inhibitors (autoantibodies) against Factor XI. Used in patients with acquired Factor XI deficiency, unexplained prolonged aPTT, or bleeding despite normal antigen levels. Helps differentiate between inherited and acquired causes of bleeding.
Plasma
6 mL (2 mL in each of 3 tubes)
Blue top (sodium citrate) tube
No special preparation is required for this test. You may eat, drink, and take your medications as normal, unless instructed otherwise by your healthcare provider.
Citrated Plasma samples should be collected by double centrifugation
| Temperature | Period |
|---|---|
| Frozen | Contact Technical Support |