A serum containing antibodies produced in response to an infection or injection of an antigen.

Serum containing antibodies produced by injecting an animal with bacterial toxins, used to provide immunity or treat specific diseases.

Serum containing antibodies produced by the body to fight off an invading antigen; used for prevention, treatment, and diagnosis. and diagnosis.

Medical treatment involving the injection of blood serum from immune animals or healthy human globulin into a patient to treat disease; immunotherapy.

serotonin; a chemical that carries messages between nerve cells in the brain and throughout the body