Serum

Definition

Serum is the clear, yellowish fluid that remains after blood has clotted and all cells have been removed. It contains proteins, electrolytes, antibodies, antigens, and other important components.

5 Must Know Facts For Your Next Test

1. Serum lacks clotting factors as they are used up in the clotting process.
2. It contains antibodies which play a crucial role in immune responses.
3. Serum is vital for diagnosing diseases because it carries biomarkers related to various conditions.
4. The complement system, part of the innate immune response, is present in serum.
5. Serum differs from plasma as plasma still contains fibrinogen and other clotting factors.

Review Questions

• What components are found in serum that make it useful for immune responses?
• How does serum differ from plasma?
• Why is serum important for diagnostic purposes?

Related terms

Plasma:

The liquid component of blood that holds blood cells in suspension and still contains clotting factors.

Antibodies:

Proteins produced by the immune system that recognize and neutralize pathogens such as bacteria and viruses.

Complement System:

A group of proteins found in blood serum that enhance the ability of antibodies to clear pathogens from an organism.