Plasma and serum are two very common terms you hear on a regular basis. Did you know that there are a number of differences between the two?
Both plasma and serum are important parts of blood. The blood comprises of plasma, serum, white blood cells (cells that fight foreign bodies) and red blood cells (cells that carry oxygen). The main difference between plasma and serum lies in their clotting factors.
A substance called fibrinogen is essential in blood clotting. The blood plasma contains this fibrinogen. Basically, when serum and plasma are separated from the blood, plasma still retains the fibrinogen that helps in clotting while serum is that part of the blood that remains after this fibrinogen is removed.
What remains of the blood once the red blood cells, white blood cells and clotting factors have been removed? Blood serum is mostly water that is dissolved with proteins, hormones, minerals and carbon dioxide. It is a very important source of electrolytes.
When you donate blood, it is separated into a number of parts, so that it can be given to specific patients. Blood is separated into proteins (albumin etc), red blood cells and white blood cells. This helps hospitals in custom treating patients. For instance, if a patient has liver failure, he may be provided blood plasma together with the clotting factors. It is also given to patients who have problems with blood clotting.
Plasma is a clear and yellowish fluid part of the blood. It is also found in lymph or in intramuscular fluids. This is the part of the blood that contains fibrin and other clotting factors. Plasma makes up about 55% of the total blood volume. The main constituent of blood plasma is water.
How do medical professionals split the various components of blood? The process is highly complicated. Blood plasma is prepared by spinning the test tube containing blood in centrifuges till the blood cells are isolated at the end of the tube. Once this has been done, the plasma is drawn off. Blood plasma normally has a density of 1.025kg/l. the wonderful thing about this plasma is that it can be stored for even 10 years from the date it has been collected. Plasma is the cell free part of the blood and it is usually treated with anticoagulants.
Serum is the liquid part of the blood after the coagulation. They contain 6-8% of the proteins that make up blood. They are more or less equally divided between serum albumin and serum globulins. When blood is extracted and left to clot, the clot shrinks after some time. The serum is squeezed out once this clot shrinks. The proteins in the serum are usually separated by a process called electrophoresis.
Summary:
1. Plasma is the part of the blood that contains both the serum and clotting factors.
2. Serum is the part of the blood that remains once the clotting factors like fibrin have been removed.
3. Plasma contains the clotting factors and water, while serum contains proteins like albumin and globulins.