Blood serum

In blood, the serum is the component that is neither a blood cell nor a clotting factor; it is the blood plasma with the fibrinogens removed. Serum includes all proteins not used in blood clotting and all the electrolytes, antibodies, antigens, hormones, and any exogenous substances (e.g., drugs and microorganisms).

The study of serum is serology. Serum is used in numerous diagnostic tests, as well as in blood typing.

This formula can be applied: Serum = plasma - fibrinogens (and other clotting proteins)