Biotin-avidin/streptavidin interaction

Liposome conjugates may be used in various immunoassay procedures. The lipid vesicle can provide a multivalent surface to accommodate numerous antigen-antibody interactions and thus increase the sensitivity of an assay. At the same time, it can function as a vessel to carry encapsulated detection components needed for the assay system. This type of enzyme-linked immunosorbent assay (ELISA) is called a liposome immunosorbent assay or LISA. One method of using liposomes in an immunoassay is to modify the surface so that it can interact to form biotin-avidin or biotin-streptavidin complexes. The avidin-biotin interaction can be used to increase detectability or sensitivity in immunoassay tests (Chapter 23) (Savage et al., 1992). 

One method of using liposomes in an immunoassay is to modify the surface so that it can interact to form biotin—avidin or biotin—streptavidin complexes. The avidin— biotin interaction can be used to increase detectability or sensitivity in immunoassay tests (Chapter 13) (Savage et al., 1992). 

Similar assays for measuring protease activity were also reported by Whitten and coworkers [49], These assays utilize polystyrene microspheres that are coated with streptavidin (a biotin-binding protein) and a biotinylated anionic fluorescent conjugated polyelectrolyte or a cationic polyelectrolyte, A biotinylated quencher-labeled peptide serves as a substrate for the enzyme and when mixed with the microspheres, a strong complex similar to the one in the DNA assays described in Section 13,3,1, through the biotin-avidin interaction is created [49], A schematic drawing of the assay is shown in Figure 13,7,... 

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