Direct agglutination assay

Definition

A direct agglutination assay is a laboratory technique used to detect antibodies or antigens in a sample by mixing it with particles that will clump together if the target molecule is present. This method is commonly used for diagnosing infections and blood typing.

5 Must Know Facts For Your Next Test

1. Direct agglutination assays involve the visible clumping of particles when antigens bind to specific antibodies.
2. They are used to diagnose diseases such as typhoid fever, brucellosis, and certain parasitic infections.
3. This assay requires no secondary antibodies or labels, making it simpler and quicker than indirect methods.
4. The sensitivity of the test can vary depending on the quality and quantity of the antigen-antibody reaction.
5. Agglutination can be observed either macroscopically (with the naked eye) or microscopically (under a microscope).

Review Questions

Related terms

Indirect Agglutination Assay: An assay where antibodies or antigens are detected using secondary reagents that cause visible clumping.

Hemagglutination:

A type of agglutination involving red blood cells as indicators for antibody-antigen reactions.

Antigen:

A substance that induces an immune response, particularly the production of antibodies.