Protein S activity


For in vitro determination of free protein S activity in human plasma samples . It can be used to assist in the detection of congenital deficiency and acquired protein S deficiency.


Protein S is a vitamin K-dependent glycoprotein and a cofactor for the expression of anticoagulation activity of activated protein C . There are two forms of protein S in plasma: 40% free protein S (with functional coactivity) and 60% protein S that can bind to C4B - . Protein S deficiency is both innate and acquired, and has been detected in oral anticoagulant contraceptives, pregnancy, patients with liver disease, and neonates. Alterations in protein S activity increase the risk of thromboembolism.


When the concentration of Normal heparin 1.5 IU/mL, low molecular weight heparin 2.0 IU/mL, bilirubin 15 mg/dL, hemoglobin 250 mg/dL had less than 10%.

Note: Certain medications (e.g., warfarin) or certain conditions (e.g., pregnancy) may affect the results of the test. If there are unexpected results, additional laboratory validation may be required.


Determination of international standard (NIBSC 03-228), the measurement of the relative deviation should15%.


For the determination of the plasma sample, the reagent is linear in the range of [10%-130%], and the linear correlation coefficient should 0.95


The control (normal control and abnorma control) were repeated 10 times with the kit, and the coefficient of variation was CV≤15%


Normal quality control plasma was tested with three different batches of reagents, and the difference between batches should be less than 15%.