The precipitin test determines

The precipitin test determines

• A. If semen is present.
• B. Whether blood is of human or animal origin.
• C. If blood is old.
• D. The elevation of body temperature.

Answer: (D)

The main idea is using an immunological reaction to identify the species origin of proteins in a bloodstain. The precipitin test employs antibodies raised against proteins from a particular species (for example, human serum). When the unknown sample is tested with that antisera, if it contains proteins from the same species, they bind the antibodies and form a visible precipitate at the zone of equivalence. This allows you to determine whether the blood is of human or animal origin. In practice, this means the test is about confirming human versus animal origin of blood, not about detecting semen, assessing how old the blood is, or measuring body temperature. Those outcomes are addressed by different tests or indicators.

The main idea is using an immunological reaction to identify the species origin of proteins in a bloodstain. The precipitin test employs antibodies raised against proteins from a particular species (for example, human serum). When the unknown sample is tested with that antisera, if it contains proteins from the same species, they bind the antibodies and form a visible precipitate at the zone of equivalence. This allows you to determine whether the blood is of human or animal origin.

In practice, this means the test is about confirming human versus animal origin of blood, not about detecting semen, assessing how old the blood is, or measuring body temperature. Those outcomes are addressed by different tests or indicators.