A chromogenic assay which measures tissue factor (TF) procoagulant activity in human plasma and cell lysates.
TF is a membrane-bound glycoprotein that serves as both the receptor and cofactor for Factor VII (fVII) and Factor VIIa (fVIIa) in initiating cell surface procoagulant activity. TF is absent on cells within the vascular endothelium or, if present, its conformation is not suitable to react with Factor VII. However, when tissue injury disrupts the vascular endothelium, the barrier separating intravascular Factor VII from TF is broken and Factor VII/TF complexes can be formed. The TF/fVIIa complex activates Factors IX and X by limited proteolysis, leading ultimately to thrombin generation and fibrin formation. When monocytes, macrophages and endothelial cells are stimulated by endotoxins, cytokines and lectins, TF is upregulated and an increase in procoagulant activity is seen.
The assay is a two stage chromogenic assay. In the first stage, the TF in the sample is allowed to complex with fVIIa to generate TF/fVIIa complexes and convert fX into fXa. In the second stage, fXa cleaves the chromogenic substrate, SPECTROZYME® fXa. The TF concentration in the sample is directly proportional to the amount of fXa activity generated.
For Research Use Only
|PRODUCT NAME||REF||# of Tests|
|ACTICHROME® TF activity assay||846||100|