For some scientists, there is a belief that the difference between serum and plasma is so minimal that it is not worth differentiating between them.
While they are both byproducts of blood after cells have been removed, this is where most similarities between the two finish.
Their most significant difference in definition, which makes the gap between them so important, is that serum is the remaining liquid left behind after the blood has clotted.
Plasma on the other hand is the liquid left after clotting has been prevented due to adding an anticoagulant.
The process of blood clotting drastically shifts its properties and composition, and this is what makes the difference between serum and plasma so important.
The proteins in the blood are altered and prothrombin is turned to thrombin which is an enzyme that turns fibrinogen into fibrin.
The anticoagulant most commonly used to help produce plasma instead of clotting to create serum is EDTA that chelates the calcium that clots blood but also inhibits other enzymes.
While EDTA is the most commonly used it is not the only anticoagulant.
So while you now know the major differences in definition that separate serum and plasma, let’s get into some more specific properties of the two that can be used to differentiate and identify them.
Appearance Of Serum And Plasma
Serum is the liquid part of the blood that remains after blood coagulates or clots. Plasma on the other hand is a clear, slightly yellow fluid part of the blood itself.
What Are They Composed Of?
Serum is composed of the water fluid that comes from blood that has not been affected by the clotting process. Plasma is the part of the blood fluid itself that contains the blood clotting agents.
Serum contains proteins, electrolytes, antigens, hormones, and antibodies. Plasma on the other hand is considered the medium of blood where red blood cells and white blood cells are suspended and transported in.
When it comes to the antibodies that compose each liquid, serum has antibodies that cross-react with a recipient antigen.
Blood plasma however, contains antibodies composed of protein that fight unwanted substances that enter the body.
The proteins that serum is composed of include albumin and globulins, while the blood plasma contains the elements that clot blood as well as water.
Serum does not feature fibrinogen while plasma does contain fibrinogen. Serum contains 90% water while plasma contains a slightly higher 92 to 95% water.
How Much Volume Do Each Have In Comparison?
Serum generally has less volume in comparison to the plasma which is the yellow liquid that composes around 55% of the total volume of the blood itself.
How Are Serum And Plasma Isolated?
Serum is usually obtained by spinning the blood after it has clotted; this process is generally more time-consuming because of the difficulty of this procedure.
Plasma is similarly obtained by spinning only before the blood has clotted and because of this is generally easier and quicker than collecting serum.
Do They Use Anticoagulants?
As previously established, serum does not require anticoagulants to isolate and separate it from blood. This is the inverse for plasma, which uses anticoagulants as a key part of the separation procedure.
How Dense Are Serum And Plasma?
Serum has an approximate density of 1.024g/ml while plasma’s approximate density is 1025kg/m3 or 1.025g/ml.
How Do Serum And Plasma Need To Be Stored?
Serum can be stored at around 2-6 degrees for several days, while plasma can be frozen and then stored for up to a year.
How Are Serum And Plasma Arranged?
In serum the cells are usually attached together in a clot formation, while in plasma the cells are not attached together and instead suspended within the plasma.
What Are Serum And Plasma Used For?
Serum is the most highly preferred part of the blood used in checking blood groups. Serum is also an important source of electrolytes with animal sera being used in antivenom, antitoxins, as well as in many important vaccinations.
Finally, serum is used for many various diagnostic tests that are used for working out the levels of cholesterol, protein, sugar, HCG and other similar substances from within blood.
Plasma while being similar to serum, has a variety of different uses that helps differentiate it from the former. Plasma is delivered to patients who are dangerously lacking in blood cells.
The proteins that are contained within plasma are used to help with the transportation of materials like glucose and other nutrients that need to be carried throughout the bloodstream.
Finally, Plasma helps with the healthy maintenance of blood pressure and also in regulating and controlling the body’s temperature.
So as you can tell from this list, there is a litany of differences between serum and plasma, and they should definitely not be treated as interchangeable.