Titer

Definition

Titer refers to the concentration of a substance in a solution, often used to measure the level of antibodies or antigens in a serum. It is determined by serially diluting the sample and identifying the highest dilution at which activity is still detectable.

5 Must Know Facts For Your Next Test

1. Titers are commonly used to assess immune responses by measuring antibody levels.
2. A high titer indicates a high concentration of antibodies, suggesting recent exposure or vaccination.
3. The endpoint titer is the highest dilution factor that still gives a positive result in an assay.
4. Agglutination assays are one type of test used to determine titers by observing clumping reactions between antigens and antibodies.
5. Fluorescent antibody techniques can also be employed to determine titers using fluorescence-labeled antibodies.

Review Questions

• What does a high titer indicate about an individual's immune response?
• How is the endpoint titer defined in laboratory analysis?
• Which assays can be used to determine antibody titers?

Related terms

Antibody:

A protein produced by B cells that binds specifically to an antigen.

Agglutination Assay: A laboratory method for detecting antigen-antibody complexes via visible clumping.

Fluorescent Antibody Technique: A method for detecting specific antigens or antibodies using fluorescently labeled antibodies.