Antigen Antibody Reaction

Refers to the strength of binding between a single antigenic determinant and an individual antibody combining site 

The equilibrium constant that describes the antigen - antibody reaction

• Affinity

• Avidity

* Measure of the overall strength of binding of an antigen with many antigenic determinants and multivalent antibodies 

* Influenced by both the valence of the antibody and the valence of the antigen 

• Affinity

• Avidity

Use fluorescein isothiocyanate labeled-immunoglobulin to detect antigens or antibodies according to test systems

• Immuno-fluorescence 

• Radio-immunoassays

• Enzyme Linked Immuno-sorbent Assay

• Chemiluminescent Immunoenzymatic Assay

Radioactive labelled-antibody (or antigen) competes with the patient's unlabeled antibody (or antigen) for binding sites on a known amount of antigen (or antibody

• Immuno-fluorescence 

• Radio-immunoassays

• Enzyme Linked Immuno-sorbent Assay

• Chemiluminescent Immunoenzymatic Assay

* Use of enzyme-labeled immunoglobulin to detect antigens or antibodies 

* Signals are developed by the action of hydrolyzing enzyme on chromogenic substrate

• Immuno-fluorescence 

• Radio-immunoassays

• Enzyme Linked Immuno-sorbent Assay

• Chemiluminescent Immunoenzymatic Assay

Process for the quantitative and qualitative determination of antigens, antibodies and their complexes by means of chemiluminescing labeling substance activated or excited to 

Chemiluminescence’s by an analytical reagent. By means of a serological reaction, initially an antigen/ antibody complex is formed which is treated with a chemiluminescing conjugate containing chemiluminescing triphenylmethane dyes and the chemiluminescene of the chemiluminescing complex formed is measured

• Immuno-fluorescence 

• Radio-immunoassays

• Enzyme Linked Immuno-sorbent Assay

• Chemiluminescent Immunoenzymatic Assay

* Fusion lines at their junction to form an arc

* Serologic identity/ presence of common epitope

• Identity

• Crossed Lines

• Partial Identity

* Demonstrates 2 separate reactions

* Compared antigens shared no common epitopes

• Identity

• Crossed Lines

• Partial Identity

Fusion of 2 lines with spur

• Identity

• Crossed Lines

• Partial Identity

* First reaction involving Ag-Ab combination 

* Single antigenic determinant on the surface particle

• Primary Phenomenon (Sensitization)

• Secondary Phenomenon (Lattice Formation)

• Direct Agglutination

• Slide Agglutination

• Tube Agglutination Test