Illustration of how diphtheria antitoxin is made;

How did they make diphtheria antitoxin?

Scientists learned to harness the immune systems of some animals to produce antitoxin serums to use as medicines. Diphtheria antitoxin was one of these medicines. Doctors used diphteria antitoxin to treat and prevent diphtheria, an often deadly childhood disease.

1. Scientists grow diphtheria-causing bacteria in the laboratory and harvest its toxin.

2. Next, researchers inject horses with the diphtheria toxin. As an immune response, the animal's blood produces diphtheria antitoxin.

3. Scientists collect blood from the horses and separate out the antitoxin rich serum.

4. Then, researchers purify the antitoxin serum for use as a medicine for people.