Plasma versus serum

Plasma and serum are obtained by taking venous blood.

Plasma
Plasma together with blood cells and elements form blood. We get it from non-coagulating whole blood. In order for the blood in the collection system not to "clot", we must prevent hemocoagulation:


 * by binding of Ca 2+ ions:
 * anion of a weak acid (citrate, oxalate,…) and salts that do not dissociate are formed;
 * as well as a chelating agent (EDTA) to form chelate;
 * surface treatment of the material of the sampling system (heparin coating).

Finally, we remove cells and cellular elements by centrifugation.

Serum
Obtaining  serum is not so complicated - we do not prevent hemocoagulation in a collection system that often contains crystals to increase the contact surface. There is hemocoagulation, a fibrin network is formed in which blood cells are also trapped. What remains "liquid" is called serum.

Centrifugation is therefore no longer necessary.

Related articles

 * Blood
 * Blood serum
 * Plasma