Test guide
Two-Stage Clotting Factor Assay
A two-staged test with purified coagulation factors in the first stage, and a FXa-specific chromogenic substrate in the second stage. In the first stage, diluted sample plasma, which has been treated with Al(OH)3 to remove prothrombin, is mixed with a combined reagent (human serum, factor V, phospholipids and calcium). In the second stage, a subsample from the first stage is mixed with normal plasma, providing prothrombin and fibrinogen, and the clotting time is measured to deduce the amount of FVIII present.
What it is for
Source: National Cancer Institute, NCI Thesaurus 26.09d, C159551. Unmodified NCI definition, CC BY 4.0. Source identity and classification checked automatically on 2026-10-20.
Limitations
Terminology reference for a laboratory procedure. The source definition does not establish routine clinical availability, validated specimen types, reference intervals, product authorization or suitability for an individual. Consult the performing laboratory for its validated method and interpretation.
Also known as
- Two-Stage Clotting Assay
- Two-Stage Clotting Factor Assay
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