Download - Chapter 6 Ag-Ab Interactions
Chapter 6 Ag-Ab Interactions
Nature of the Ag-Ab interaction
Immunological assays
4 types of noncovalent forces
AffinityThe strength of the total noncovalent interactions between a single Ag-binding site on an Ab and a single epitope is the affinity of the Ab for that epitope.
AvidityThe strength of multiple interactions between amultivalent Ab and Ag is called the avidity.
Example: secreted pentameric IgM often has a lower affinity than IgG, but the high avidity of IgM, resulting from its higher valence, enables it to bind Ag effectively.
Immunological Assays
1. Precipitation
2. Agglutination
3. Radioimmunoassay
4. Enzyme-linked Immunosorbent Assay
5. Western Blotting
6. Immunofluorescence
7. Flow Cytometry and Fluorescence
8. Immunoelectron Microscopy
Precipitation Reactions:
Precipitation in fluidsPrecipitation in gels - radial immunodiffusion (Mancini method) - double immunodiffusion (Ouchterlony method)Immunoelectrophoresis
Precipitation Reactions
Lattice Formation(格子 )
Double Immunodiffusion (Ouchterlony method)
Immunoelectrophoresis
Agglutination Reactions:
HemagglutinationBacterial AgglutinationPassive AgglutinationAgglutination Inhibition
Hemagglutination
Agglutination No Agglutination No Ab
Agglutination Inhibition
Solid-phase Radioimmunoassay (RIA)
Enzyme-linked Immunosorbent Assay (ELISA):
- Indirect ELISA
- Sandwich ELISA
- Competitive ELISA
- Chemiluminescence
Elispot Assay
Western Blotting
Immunofluorescence
Flow Cytometry
FACS:
Fluoresence-activatedCell sorter
Immunoelectron microscopy