Serum

Serum is the component that is neither a blood cell (serum does not contain white or red blood cells) nor a clotting factor; it is the blood plasma not including the fibrinogens. Serum includes all proteins not used in blood clotting (coagulation) and all the electrolytes, antibodies, antigens, hormones, and any exogenous substances (e.g., drugs and microorganisms). A study of serum is serology, and may also include proteomics. Serum is used in numerous diagnostic tests, as well as blood typing.

Composition

Serum is an essential factor for the self-renewal of embryonic stem cells in combination with the cytokine leukemia inhibitory factor.

Blood serum and plasma are one the largest source of biomarkers, whether for diagnostics or therapeutics. Its vast dynamic range, further complicated by the heterogeneity of population, makes it a complex system to study.

Clinical significance

Serum is the substance that is screened in Type I diabetes to identify autoantibodies.

Serum albumin, commonly measured by laboratories, is often used as an indicator of liver disease such as cirrhosis. If serum albumin is found to be low, further investigation is required to determine the cause.

See also

• Blood plasma
• Serology
• Serum albumin
• Serum protein electrophoresis