Serum or plasma concentration of vitamin K-dependent coagulation factor (e.g., protein C)

What This Test Measures

Your blood sample is tested for the presence of protein C, a natural anticoagulant that helps prevent abnormal blood clots. The test checks its concentration in your serum or plasma.

Why It Matters in Medicine

Protein C plays a critical role in maintaining blood flow by preventing clots from forming where they shouldn’t. Low levels can increase the risk of clotting disorders, while high levels may suggest certain blood disorders.

Common Reasons for Testing

Doctors may order this test if you have symptoms of bleeding problems (e.g., easy bruising, excessive bleeding), a history of clotting disorders, or if you’re taking blood thinners. It’s also used in monitoring conditions like thrombophilia or after trauma.

Sample Collection and Preparation

A blood sample is drawn from a vein, typically in your arm. The sample is sent to a lab where it’s separated into serum (liquid part after clotting) or plasma (liquid part before clotting). The protein C level is then measured using a specialized immunoassay or similar method.