Related Experiment Video
Updated: Aug 8, 2026

A Microfluidic Flow Chamber Model for Platelet Transfusion and Hemostasis Measures Platelet Deposition and Fibrin Formation in Real-time
Published on: February 14, 2017
Newer concepts of blood coagulation
H R Roberts1, D M Monroe, J A Oliver
1Center for Thrombosis and Hemostasis, University of North Carolina at Chapel Hill, USA.
Abstract:
In this report we describe an in vitro model of blood coagulation reactions that mimics as closely as possible the in vivo condition. Our model indicates that the tissue factor-factor VIIa complex initiates coagulation by activating small amounts of both factor IX and factor X in the environment of the tissue factor bearing cell. Factor Xa and factor IXa formed in the initial reaction then play very distinct roles in the subsequent interactions of the clotting mechanism leading to a burst of thrombin generation on the platelet surface. Our results also indicate that factor XI can be activated by thrombin in the absence of factor XII and that the function of factor XI is simply to enhance conversion of factor IX to factor IXa resulting in enhanced thrombin generation on the platelet surface.
Related Concept Videos
Coagulation
Anticoagulant Drugs: Low-Molecular-Weight Heparins
Introduction to Hemostasis
The three phases of hemostasis involve many clotting factors present in plasma and several substances released by platelets and injured tissue cells. It is a fast, localized, and...
Coagulation
During the coagulation phase, clotting factors, or procoagulants, play a vital role in initiating and progressing the coagulation cascade. This cascade is a series of reactions...
Extrinsic and Intrinsic Pathways of Hemostasis
The Extrinsic Pathway
The extrinsic pathway of coagulation is typically initiated by tissue damage that exposes blood to tissue factor (TF), a protein released by the damaged tissue cells outside the blood vessels—this interaction with TF triggers biochemical reactions involving specific clotting factors. The key player here is Factor VII, which forms a...
Clot Retraction and Fibrinolysis

