What happens in the precipitin test when human blood is injected into an animal?

What happens in the precipitin test when human blood is injected into an animal?

• A. The animal becomes immune to human blood.
• B. The animal produces antibodies against its own blood.
• C. The animal produces antibodies that react specifically with human antigens.
• D. The animal digests the human blood and shows no reaction.

Answer: (C)

The precipitin test hinges on producing antibodies that are specific for human proteins and then using those antibodies to detect human antigens. When human blood is introduced into an animal, the animal’s immune system recognizes the human proteins as foreign and mounts an antibody response, creating antibodies that are specifically targeted to human antigens. These anti-human antibodies will bind to human proteins if they are present in a sample, and under the right conditions this binding forms a visible precipitate. This is why the correct interpretation is that the animal can produce antibodies that react specifically with human antigens. It isn’t about the animal becoming immune to whole human blood, nor does it involve the animal digesting blood without reaction, nor does it describe antibodies against the animal’s own tissues.

The precipitin test hinges on producing antibodies that are specific for human proteins and then using those antibodies to detect human antigens. When human blood is introduced into an animal, the animal’s immune system recognizes the human proteins as foreign and mounts an antibody response, creating antibodies that are specifically targeted to human antigens. These anti-human antibodies will bind to human proteins if they are present in a sample, and under the right conditions this binding forms a visible precipitate. This is why the correct interpretation is that the animal can produce antibodies that react specifically with human antigens. It isn’t about the animal becoming immune to whole human blood, nor does it involve the animal digesting blood without reaction, nor does it describe antibodies against the animal’s own tissues.