Serum vs. Plasma

Blood is a fluid connective tissue that moves throughout the body by transporting essential nutrients, oxygen, and metabolic wastes. It is also involved in the regulation of the body's temperature and the pH by interacting with acids and bases.

Blood is mainly composed of red blood cells (RBCs), white blood cells (WBCs), plasma, and serum. Plasma and serum are the main components of blood and are commonly used in blood group testing experiments to determine a patient's blood group.

Plasma and serum can be separated by centrifugation of blood on the basis of weight, size, and density.

What is Plasma?

Plasma is the fluid part of blood, present in the majority of the other components of blood. Since this is the liquid part of the blood, a lot of nutrients and proteins are dissolved here and it also plays an important role in the process of transportation.

Here are the key characteristics about plasma:

1. It is light amber in color and blood cells are not present in the plasma. It contains proteins and other blood components as a suspension.

2. It accounts for 55% of the entire blood volume and in itself, it is about 95% water by volume.

3. It has dissolved proteins such as serum albumins, globulins and fibrinogen.

4. It is the main medium for waste transportation and thus, contains carbon dioxide as well.

5. It also contains electrolytes of Sodium, Calcium, Magnesium and Chlorine etc.

6. It can be obtained by the process of centrifugation with the help of an anticoagulant. For rapid testing, filtration can also be used to obtain plasma.

7. The density of blood plasma is 1025 kg/m³.

Here are the main functions of plasma:

1. Transportation of waste products.

2. Balances electrolyte concentrations, thus preventing infections and blood disorders.

3. Clotting of blood in case of wounds.

4. Balancing PH helps the cells function normally.

5. Balancing body temperature.

What is Serum?

Serum is a solute of the blood that works just like plasma except that it does not help in blood clotting. Being fluid, it also contains various proteins as well as electrolytes and antibodies dissolved in it. But like plasma, serum also does not contain RBCs, WBCs or platelets.

Here are the key characteristics about serum:

1. It is a solute component of blood without any clotting properties.

2. It contains electrolytes, proteins, antigens and other hormones along with exogenous substances like drugs.

3. WBCs, RBCs and platelets are not present in serum.

4. It is obtained by coagulating blood, followed by its centrifugation.

Here are the main functions of serum:

1. Helps in the detection of the presence of drugs.

2. Used in immunotherapy, that is, the treatment of a disease whose antibodies are present in the serum.

3. It is also used in protein electrophoresis.

Advantages and Disadvantages of Plasma and Serum

When comparing the use of plasma and serum in research or healthcare settings, researchers need to consider their advantages and disadvantages for specific applications.

Plasma provides a richer source of blood components, including blood cells, clotting factors, and various proteins, making it a suitable choice for a wide range of tests. Its versatility enables researchers to carry out proteomics, metabolomics, and coagulation studies with the same sample.

The main disadvantage of using plasma is its specialized collection and storage requirements, which may be more time-consuming and costly compared to serum. Plasma samples require the use of anticoagulants during collection, and proper storage conditions must be maintained to avoid contamination or degradation of analytes.

A significant advantage of serum is its simplicity of collection and storage. It requires only blood clotting and centrifugation to separate the serum from the cellular components. Additionally, serum is commonly used in diagnostic testing such as serological testing and biomarker discovery, making it a familiar and standardized choice for many labs.

Despite its advantages, serum has some limitations. Its major drawback is the lack of clotting factors, which are essential for coagulation studies. Moreover, serum samples may be affected by interference from coagulation or hemolysis, potentially leading to errors in biomarker measurements.

The choice between plasma and serum depends on the specific needs and objectives of the research or healthcare project. The type of analytes of interest, available equipment and resources, and sample processing considerations should be carefully evaluated to determine the most suitable biospecimen for study.

Creative Bioarray offers collections from healthy human or disease state donors as well as a diverse array of animal species.

• Whole blood
• Serum
• Plasma
• Buffy coat
• Red blood cells
• Leukocytes
• Platelet concentrates
• Diseased peripheral blood
• Maternal blood
• Cord blood
• Whole bone marrow