The clear yellowish liquid obtained upon separating whole blood into its solid and liquid components after it has been allowed to clot.

plural of serum

Relating to serum.

(medicine) The clear fluid obtained from whole blood by removing blood cells, platelets and fibrinogen; it is blood plasma without the fibrinogen.

An allergylike reaction to proteins in antiserum derived from animal sources.

plural of blood serum

(informal, medicine) A psychoactive medication, especially one administered by injection, which supposedly renders a person cooperative and disposed to respond honestly to questions.

plural of serum sickness

plural of truth serum

(medicine) A blood serum created from the blood plasma of a person who has recovered from an infectious illness, which contains antibodies to the infectious disease factor (such as viruses). For convalescent serum therapy, the disease antiserum created from the plasma can be injected into an ill victim of that disease as a treatment.