The serum.
blood serum is blood plasma without the fibrinogen or blood clotting factors
fibrinogen
fibrinogen is one of the plasma proteins and it has the main role in the clotting process as it is converted by the effect of thrombin ( active enzyme ) into fibrin that accumulates forming a network that block the injured blood vessel
Blood is what a chemist would describe as an aqueous solution; the liquid part is simply water.
Plasma and blood cells are different components of blood. When cells are removed form blood the remaining fluid is plasma. When clotting factors present in the plasma interact with blood cells, a clot forms. Clotted blood do not have plasma. The fluid remains after the blood clots is called serum.
This is a test that evaluates the level of fibrinogen in the blood. Fibrinogen is one of the major proteins in the blood involved in clotting. Elevated levels can indicate a systemic inflammatory problem, while low levels may indicate poor clotting or liver failure.
When blood clotting is activated, fibrinogen (a protein of the blood plasma) circulating in the blood is converted to fibrin, which in turn helps to form a stable blood clot at the site of vascular disruption.
Blood Plasma minus clotting factors is called the 'Serum'.
Serum because it has no fibrinogen or it has no clotting factors.
Fibrinogen
Plasma has clotting factors in it and serum does not.
fibrinogen