8. Precipitation Reactions FIGURE- Precipitation reactions in fluids yield a precipitin curve. ( Lattices or large aggregates ) ( no precipitate is formed if an Ag contains only a single copy of each epitope )
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11. Precipitation Reactions Diagrammatic representation of radial & double immunodiffusion. : Precipitation reactions in gels yield visible precipitin lines; no visible precipitate forms in regions of Ab or Ag excess. in the Ab-containing semisolid medium The region of equivalence -> The area is proportional to the conc. of Ag.
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22. FIGURE 6-8 - The original home pregnancy test kit employed hapten inhibition ( agglutination inhibition ) to determine the presence or absence of h uman c horionic g onadotropin (HCG) >>> The kits currently on the market use ELISA-based assays . -Also used to determine the use of illegal drugs, & immunity (Ab) to virus (rubella). Agglutination inhibition Reactions
38. ELISA Variations in the enzyme-linked immunosorbent assay (ELISA) technique, similar to RIA except using an Enzyme (alkaline ⓟ, horseradish peroxidase, & β-galactosidase) : safer & less costly. to detect Ab (HIV, HCV) to detect Ag , For e.g- HCG to detect Ag
45. Western blotting : separates the components according to their molecular weight. : the proteins in the gel are transferred to the sheet of nitrocellulose or nylon by the passage of an electric current. : probed with Ab & then radiolabeled or enzyme-linked 2 nd Ab. : a position is visualized by means of an ELISA reaction. Expose x-ray film and develop
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