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Updated: Jul 18, 2026

Measurement of Factor V Activity in Human Plasma Using a Microplate Coagulation Assay
Published on: September 9, 2012
[Factor XIIa-inhibited diluted thromboplastin time can reflect coagulation process]
1Department of Hemostatic Physiology, Hunan Medical University, Changsha 410078, China.
This study introduces a novel screening test for coagulation, the FXII ai DTT assay, which effectively reflects the two-stage coagulation process. The findings confirm Factor XI's crucial role in the amplification stage.
Area of Science:
- Coagulation cascade physiology
- Hemostasis research
- Biochemical assays
Context:
- The coagulation process involves complex, multi-stage enzymatic reactions.
- Accurate assessment of coagulation is vital for diagnosing and managing bleeding disorders.
- Existing screening tests may not fully capture the nuances of all coagulation stages.
Purpose:
- To develop and validate a new screening test capable of reflecting the distinct stages of the coagulation process.
- To investigate the role of Factor XI (FXI) in the amplification phase of coagulation.
- To assess the practicability of the FXII a-inhibited diluted thromboplastin time (FXII ai DTT) assay.
Summary:
- The study utilized FXII a inhibition and varying thromboplastin concentrations to observe clotting times.
- Results indicated that FXII ai DTT is sensitive to Factor XI levels and reflects FXa generation dynamics.
- Data support a two-stage coagulation hypothesis, highlighting FXI's amplification role.
Impact:
- The developed FXII ai DTT assay shows potential as a practicable screening tool for evaluating coagulation.
- This research enhances understanding of the coagulation cascade, particularly the amplification stage.
- Provides a foundation for improved diagnostic methods in hemostasis.
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