Lecture on Precipitation and Agglutination

These flashcards cover key vocabulary and principles related to precipitation and agglutination, as discussed in the lecture.

Affinity

The force of attraction between a single Fab site and an antigen.

Avidity

The overall strength of the binding of all the antibody-antigen sites.

Law of Mass Action

Free reactants are in equilibrium with bound reactants.

K (Equilibrium constant)

Reflects how strongly binding occurs; calculated as [AgAb] / ([Ag][Ab]).

Turbidimetry

A method to measure the amount of light lost when passed through a sample, indicating precipitation.

Passive Immunodiffusion

A method used to detect antigen-antibody reactions in a gel medium without using electric current.

Electrophoresis

Charged proteins migrate in an electric field based on size and charge.

Hemagglutination

A type of agglutination that involves red blood cells.

Direct Agglutination

Occurs when antigen is naturally found on a particle.

Passive Agglutination

Uses particles coated with antigens that don't naturally appear on their surfaces.

Reverse Passive Agglutination

Particles are coated with antibody instead of antigen.

Agglutination Inhibition

Soluble and particulate antigens compete for a limited amount of antibody.

Flocculation

Involves fine particles (floccules) from a reaction between soluble antigen and antibody.

Dilution

The ratio of solute to solvent, such as 1:10.

Titer

The highest dilution at which a reaction is still observed.

Clinical Use of Precipitation

Quantifying immunoglobulins and detecting fungal antigens.

Clinical Use of Agglutination

ABO/Rh typing, CRP detection, rheumatoid factor testing.

Clinical Use of Electrophoresis

Diagnosing multiple myeloma and monoclonal gammopathies.

Cold Agglutinin Testing

Autoantibodies (usually IgM) agglutinate RBCs at low temperatures.