The key difference between plasma and serum is that plasma is a watery part of anticoagulated blood and consists of clotting factors like fibrinogen while serum is plasma without clotting factors, i.e., fibrinogen.
Plasma vs. Serum
Blood is the most important fluid of the body. It circulates through the arteries, veins and capillaries and plays a vital role in the transportation of different material to or from all cells of the body like oxygen and waste metabolites, etc. Blood comprises 8% of the total body weight. It is composed of red blood cells, white blood cells and platelets. It consists of two other parts, i.e., plasma and serum. People considered that both terms are same, but there exists a fine line of difference between them. The liquid part of the blood that has clotting factors like fibrinogen is called plasma while the watery part of blood devoid of clotting factors is known as serum. So, plasma is obtained before the coagulation of blood while serum is obtained after coagulation. The serum has a volume less than that of plasma.
What is Plasma?
That liquid part of the blood where the components like cells, nutrients and hormones, etc. floats is known as plasma. Plasma comprises 55% of the total blood. It is composed of water, amino acids, albumins, globulins, enzymes, gasses, nutrients, nitrogenous wastes, electrolytes and fibrinogen, etc. Fibrinogen is a blood clotting factor that is present in plasma and helps in clotting blood in case of any injury. It can be stored for years and easily transported from one place to another.
- Plasma performs various important functions given below.
- It contains many important proteins that are involved in the transportation of material throughout the body such as glucose etc.
- It helps in regulating the body temperature.
- It maintains the blood pressure.
- In the case of hemophilia and other such diseases, it is used for transfusion to the patient.
To extract plasma, take a small amount of blood sample in a test tube and add some anticoagulant factors in it, like EDTA, etc. Centrifuge it for some time. According to their weight and density, blood components will be separated into three layers. The lowermost layer is of red blood cells and appears of red color. The second layer is white and contains white blood cells and platelets. The topmost layer is of plasma and is yellow. Extraction of plasma is easy and less time to consume than serum.
What is Serum?
The fluid part of the blood which is devoid of clotting factors is known as serum. The serum is composed of water, amino acids, albumins, globulins, enzymes, gasses, nutrients and nitrogenous wastes, etc. Fibrinogen which is a clotting factor is absent in it. It contains antigens, antibodies (IgG, IgM, IgE, IgD, IgA), proteins, electrolytes and hormones. It can be stored for months.
- In the medical field, serum is used to diagnose a number of diseases like sugar, blood pressure and cholesterol, etc.
- It is also used to find the type of blood group.
To extract serum, take a small amount of blood sample in a test tube. There is no need to add any anticoagulant. Centrifuge it for some time. After 30 minutes of centrifuging, blood will clot. It will show two types of layer. The upper layer is that of serum and the lower layer is that of clotted blood. Extraction of serum is tough and more time-consuming.
- The fluid part of the blood that has clotting factors is known as plasma while fluid part of the blood devoid of clotting factors is known as serum.
- Plasma contains fibrinogen while fibrinogen is absent in serum.
- Plasma needs anticoagulants like EDTA and Heparin etc. while Serum does not need any anticoagulant.
- Plasma is obtained by centrifuging blood before clotting while serum is obtained after blood clotting. So, it is more tough and expensive to extract serum.
- Plasma comprises 55% of the total blood while serum contains less volume of
- Plasma has a 1.025 g/ml density whereas that of serum is 1.024 g/ml.
- Plasma consists of 92-95% water, but the serum is consists of 90% water.
- Plasma is used for transfusion to that patient who lacks blood cells like hemophilia while serum is used for diagnosing different diseases and for checking blood groups.
From the above discussion, it is concluded that both plasma and serum are important components of blood but with their own set of functions. Plasma is the fluid part of blood with clotting factors like fibrinogen and used for transfusion to patients. The serum is that liquid part of the blood which is devoid of clotting factors and is used for diagnosing diseases the blood type.