Serum and plasma are closely related, and similar enough that they are confused for one another, but have different uses. Blood serum is the clear liquid that remains after blood clots. Serum in a body is a component of plasma, as blood plasma is composed of a combination of both serum and coagulants.
However, when separated from those coagulants through the use of a centrifuge, serum can be used to conduct a number of medical tests, and it can also be used to develop antiserum — used to help transfer resistance to disease from one body to another. Blood serum and blood plasma are commonly confused for each other, for good reason: serum is a component of plasma.
Both are the liquid medium that blood cells move through, but the core difference is the presence of the coagulants that allow blood clots to form. When those coagulants are present, the liquid is referred to as plasma, but when removed, what remains is serum alone. This is effectively the serum definition in biology. In the medical world, the distinction is important: While a sample of blood plasma allows for a better understanding of the blood's condition as it circulates through a given body, a blood serum sample removes most of the cells and platelets that may interfere with the process of testing for certain diseases and conditions.
Though it has similarities to plasma, and is extracted in the same way — by being drawn out of the body through a vein, then run through a centrifuge — blood serum has uses that plasma is ill-suited for. The blood cells and platelets that make up about 45 percent of the blood are separated by centrifugal forces to the bottom of a specimen tube, leaving the plasma as the upper layer. The plasma also contains the coagulation factors and antibodies. Serum, the plasma component of blood which lacks coagulation factors, is similar to interstitial fluid in which the correct composition of key ions acting as electrolytes is essential for normal functioning of muscles and nerves.
Other components in the serum include proteins, which assist with maintaining pH and osmotic balance while giving viscosity to the blood; antibodies, or specialized proteins that are important for defense against viruses and bacteria; lipids, including cholesterol, which are transported in the serum; and various other substances including nutrients, hormones, metabolic waste, and external substances, such as drugs, viruses, and bacteria.
Human serum albumin, the most abundant protein in human blood plasma, is synthesized in the liver. Albumin, which constitutes about one-half of the blood serum protein, transports hormones and fatty acids, buffers pH, and maintains osmotic pressures. Immunoglobin, a protein antibody produced in the mucosal lining, plays an important role in antibody mediated immunity.
To collect plasma, an anticoagulant is added to the centrifuged whole blood, which can impact testing. EDTA is the most commonly used anticoagulant in clinical diagnostic labs. EDTA chelates the calcium needed for clotting, but can also inhibit other enzymes. There are many other anticoagulants in use such as citrate, heparin, and fluoride, each with appropriate uses. If you use only one, you could be misled by false results. For example, clotting factors in serum or the platelets and cellular elements that contaminate plasma could interfere with or alter your results.
If your results are the same for serum and plasma, then you have more flexibility in sample usage. View all of our available serum and plasma samples , including normal donors, diabetic donors, RA donors, SLE donors, and donors with other disease states.
She has a strong background in cell-based therapeutics and immunology, including a Ph. Learn more about Dr. Why is plasma volume more than serum volume in blood? I think that may be a technical difference, not an actual difference in volume.
You can get more serum if you allow the clot to contract, which it will do over the course of an hour or so. The platelets in the clot will pull it together tightly and squeeze the serum out. Otherwise when we are collecting serum we leave some behind just to avoid the rbc. Please sir, I need a clarification on some issues 1 what are the biochemical parameters used 2 when talking about biochemical parameters which of this do you use blood, plasma or serum.
I will be grateful if my questions are treated with utmost urgency. Thank you for your time. I would refer you to the table that details a few of the differences between plasma and serum.
We did not discuss the use of whole blood in this post, only the differences between plasma and serum.
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