:Normal range
Free: 80-120 % of normal plasma activity
Total 13-21 mg/L
Comment: Protein S is synthesized in the liver, it enhances the anticoagulant action of activated protein C as a cofactor. In normal human plasma, protein S exists in two forms: free (about 40%) and bound to CC4b-BP (about 60%). Only the free form expresses biological activity while the bound one is functionally inactive
Sample: Citrated plasma