Precipitin

Definition

Precipitin is an antibody that reacts with a soluble antigen to form a visible precipitate. It is commonly used in immunological assays to detect the presence of specific antigens.

5 Must Know Facts For Your Next Test

1. Precipitins are involved in the formation of antigen-antibody complexes that result in a visible precipitate when they react.
2. The precipitin reaction occurs optimally when the concentrations of antibody and antigen are equivalent, known as the zone of equivalence.
3. Precipitin tests can be used to identify bacterial species, diagnose infections, and verify the purity of an antigen.
4. In gel diffusion assays such as Ouchterlony double diffusion, precipitin lines indicate the presence and interaction of specific antigens and antibodies.
5. Precipitin reactions can be affected by factors such as temperature, pH, and ionic strength.

Review Questions

• What is the role of a precipitin in immunological assays?
• How does the zone of equivalence influence the formation of a visible precipitate?
• What factors can affect the outcome of a precipitin reaction?

Related terms

Antigen-Antibody Complex: A complex formed when an antibody binds to its specific antigen.

Ouchterlony Double Diffusion: A technique used to analyze the specificity and quantity of antibodies or antigens.

Zone of Equivalence: The optimal ratio at which antibody and antigen concentrations are equal, leading to maximal precipitation.