Antitoxin
Antitoxin, an tee TOK sihn, is a substance made by living cells that counteracts illness caused by a toxin. Toxins are poisons produced by living organisms, such as bacteria. Doctors use antitoxins to treat diseases, including tetanus (lockjaw) and diphtheria. Antitoxins are a kind of antibody that can cure or prevent diseases or make them milder (see Immune system).