What does blood plasma contain that blood serum does not

Serum and plasma both come from the liquid portion of the blood that remains once the cells are removed, but that's where the similarities end. Serum is the liquid that remains after the blood has clotted. Plasma is the liquid that remains when clotting is prevented with the addition of an anticoagulant.

Serum does not contain white blood cells (leukocytes), red blood cells (erythrocytes), platelets, or clotting factors.

Terms in this set (50) What is the difference between serum and plasma? Plasma is the liquid portion of unclotted blood and still contains the clotting factors. Serum is the liquid portion of blood that has been allowed to clot.

Serum and plasma are both liquid components of blood. Both are mainly made up of water, and both contain electrolytes, antibodies, nutrients, waste products, and other proteins. However, blood plasma also contains blood cells and clotting factors, whereas blood serum does not.