serum vs plasma

                 Before going into depth of serum vs plasma, we need to consider first the source or site in which these two components are present which is the whole blood itself. So, whole blood plays an important role in the excretion of Co2, transportation of oxygen and essentials proteins, nutrients throughout the limbs and organs of the body via the help of arteries and veins.

                        Plasma and serum are found in the soluble or fluid form in the whole blood with the presence of all other constituents such as RBC, WBC, and platelets. Plasma and serum possess certain properties which make them differ from each other as one of the factors is that plasma has a clotting agent within its fluid which is absent in the case of blood serum.

As far as, we concerned about the fact that both of these exist in a fluid state but the question that arises is, how can we decide which part is plasma and so is serum? So, by the process of centrifugation, we’ll make that possible and separate both the content from each other.

                            In this article, we will be covering the similarities, characters, functions, certain factual things, and various differences between plasma and serum Or their comparison as serum vs plasma which you may found informative and knowledgeable.


  • Difference between plasma and serum

  • Serum vs Plasma

  • Similarities

  • History and facts

  • Conclusion


Various key points of difference between plasma and serum are as follows:

serum vs plasma

  • Plasma contains the yellow part of the fluid in the blood which roughly consists 55% of the whole blood volume all along with some clotting agents, albumin, globulin, enzymes, and water. On the other hand, blood serum includes the composition of protein, amino acids, nutrients, antigens, antibodies, and some electrolytic factors.

  • It is easier to separate plasma from the blood via performing the centrifugation process as it takes very little time to refine the content of plasma from the components of whole blood whereas the separation process of blood serum is much difficult than that of plasma as it requires a whole bunch of time to separate and then settle down.

  • The overall volume of plasma in the whole blood is 55% approximate with the density of 1.025g/ml, On the contrary, the blood serum has an average amount of volume which is lesser than that in plasma and has a density that is almost similar to plasma i.e., 1.024g/ml.

serum vs plasma

  • Plasma is obtained by the spinning process which is being done with the blood cells further; an anticoagulant agent (such as EDTA, warfarin) is added to the whole blood component and the top layer which appears light in color is the required plasma. The same centrifugation process follows for obtaining the blood serum but when it comes to serum, we are not required to pour the anti-coagulating factors.

  • Plasma is partially responsible for controlling whole blood pressure and regulating the temperature in the human body. While the usage of blood serum is most likely to be seen in the vaccines or any type of anti-venom to kill the effects of toxicity. And serum also plays an important role in the diagnosis of a disease like cholesterol, sugar, etc.



serum vs plasma

      BASIS            PLASMA           SERUM
DefinitionPlasma is that part of the blood which exists in a fluid state and appears light yellow.Whereas blood serum exists in liquid form also and it too consists of the component of whole blood.
DensityThe density of plasma in blood cells is somewhat close to 1.025g/ml.On the contrary, serum density is almost the same as that of plasma which is 1.024g/ml as differs with few decimal.
Anticoagulants agentsIn the separation process of plasma, anticoagulants agents are needed to add in the content of whole blood, like EDTA, heparin afterward it got separated.While no anticoagulant agents are required to be added to the blood during the separation process as it got separated without any additives.
VolumeIt comprises 55% of the total volume of whole blood which contains mostly the nutrients and proteins in a fluid state.On the other hand, the volume of blood serum comparatively less than that of plasma which contains the rest part of the blood with other contents.
  Composition  The fluid of plasma is composed of various nutrients, vitamins and enzymes, and many more microelements that have an essential place or role in blood cells.  Whereas in the case of blood serum, the composition of minerals includes proteins, and amino acids with the presence of RBC, WBC, and platelets within it.
Fibrinogen existenceThere is a presence of fibrinogen to be seen in the plasma.While if we talk about serum then fibrinogen likely to be absent in blood serum.
Acquired viaPlasma is obtained by the continuous spinning motion in a lab machinery container. In which the blood cells needed to centrifuge to obtain the yellow fluid content called plasma.On the other hand, a similar process of centrifugation needs to be followed for separating the content of blood serum from the homogenous mixture of whole blood which includes different compounds and substances.
ConservationPlasma can be preserved up to many years say for like 10yrs and even more, as its captivity rate is longer.The blood serum has a low life expectancy, it can be saved and conserved for a couple of months, not more than that as they have a shorter life cycle.
  Water concentration  It consists of 92% to 95% of water in its fluid that includes matter like glucose, salts, lipids, etc.  Whereas on the blood serum side, the concentration level of water is roughly 90% of the total serum that consists of various minerals and proteins.
ImportancePlasma controls and regulates the whole blood pressure and body temperature of human beings.Blood Serum too very helpful and plays an important role in healing and diagnosing diseases like cholesterol, HCG, and sugar.
Procedure of separationIt is very easy to separate the content of plasma from blood cells as it takes very little time in settling down the component of whole blood.While the separation procedure of blood serum is very time-consuming and difficult too, it takes an hour of effort during the entire process.
UsagePlasma is partially held responsible for carrying and transporting vitamins, nutrients, and glucose via the bloodstream throughout the entire body.Whereas the usage of serum is most likely to be seen in making doses of anti-venom and vaccines.

Similarities between Plasma And Serum

serum vs plasma

Various similarities that fall between plasma and serum are as following mention below:

  • Firstly, both plasma and serum are the major components of blood with the presence of contents such as RBC, WBC, and blood platelets.

  • Plasma and serum both exist in the fluid state of matter and have an appearance that is too common i.e. light yellow.

  • Both serum and plasma consist of almost the same minerals and substance which is being found in them such as glucose, nutrients, proteins, vitamins, amino acids, etc.

  • And for testing the blood group of any person for instance, if a person gets affected by any disease then both serum and plasma have been taken as a sample for further study of blood cells to find out whether by which microorganism that person may get attack with.

  • Plasma and serum also share a common relationship in antigens and antibodies as both are composed of these in their liquid matrix and which are equally helpful in the diagnostic stage of cells.

  • The separation or isolation procedure of both the content plasma and serum from the blood is been done by using the same technique i.e., centrifugation process.

In March 1918, a biochemist named Gordon R. ward discovered the use of plasma, the content of the blood.  And one fact about plasma is the attachment of cells is not together which means they are suspended in the fluid matrix. Whereas in serum due to the formation of clotting, the structure of cells is attached.

The contents of plasma impact the growth hormone in a positive way which is essential for the growth and development of muscles and bones in the human body. And it too gave its rightful hand in getting rid away of the waste from the cell itself.

serum vs plasma

While in the case of serum, Karl Landsteiner is the man behind the discovery of serum which he makes it familiar to the world in the year 1901 and he is the one who even after research gave name to different blood group and that’s how he gets to know that wide variety of blood exist for which the light yellow fluid name ‘serum’ is responsible.

The serum does not contain white blood cells (i.e. leukocytes), blood platelets, and red blood cells which are scientifically termed erythrocytes. The serum of the infected people who will get recovered later from the disease plays a vital role in the field of science as antibodies of that person is quite strong which will further come into use for the treatment of any other person who will also get to suffer from the same disease.


In the following article, we concluded that both plasma and serum are equally responsible and important for the life process of blood cells as they are the major components of whole blood and they act as the backbone of the blood cells.

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