Dia-PROTEIN S

Code: 07207
4 x 1 ml
Dia-PROTEIN S
INTENDED USE
 
For the determination of functional Protein S levels in human plasma by clotting assay.Protein S is a vitamin K-dependent protein synthesized in the liver, vascular endothelium, and megakaryocytes, which plays an important physiological role in the Protein C Anticoagulant System. This anticoagulant system is one of the major regulators of haemostasis by inhibiting clot formation and by promoting fibrinolysis. Protein S functions as a cofactor for activated Protein C on the vascular membrane to facilitate the degradation of clotting factors Va and VIIIa, down-regulating clot formation. In normal plasma approximately 40% of Protein S circulates as a free molecule, while 60% is complexed with C4b, a plasma protein of the classical complement pathway. Only Free Protein S is functionally active and able to bind to activated Protein C, while the complexed form of Protein S is not. The Dia-PROTEIN  S (Clot) assay determines the amount of functional Protein S in plasma. In this assay, dilutions of normal plasma are mixed with Protein S depleted plasma. The mixed plasma is then activated by reagents which contain activated protein C, other human plasma proteins and phospholipids. After activation, clotting is initiated by the addition of calcium chloride. Human aPC and other plasmaproteins are added at such quantities, so as to normalise any deficiencies in the patient sample, preventing false positive or negativeresults forProtein S functionality. The prolongation of the clotting time is thus directly related to the concentration of the Protein S in the patient plasma.