Enzyme-linked immunosorbent assay conjugate testing

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). 

To assess the activity of a-gal-mannose glycoconjugates binding to the anti-Gal antibodies, a previously reported inhibition-type enzyme-linked immunosorbent assay (ELISA) was conducted [21]. Mouse laminin having a-gal epitopes were fixed on ELISA plate as solid phase antigens. Test glycoconjugates were then incubated with human anti-Gal antibodies on the ELISA plate. The plate was washed and incubated with horseradish peroxidase (HRP) conjugated anti-human IgG antibody. 

The use of immunoassay techniques for the determination of PAHs has been reviewed. Immunoassay is based on the coupling of a specific biological antibody in the detection device with the analyte either directly in water or extracted from solid samples and diluted in buffer solution. Enzyme-linked immunosorbent assay (ELISA) is the most common immunoassay technique employed in commercially available test kits. Water samples or soil extracts are added with an enzyme conjugate reagent to immobilized antibodies where the conjugate competes with PAHs for binding to the antibodies. ELISA test kit sensitivity and crossreactivity depends on the PAH used to raise the antibody. Antiphenanthrene or antffluoranthene antibodies raised in host animals are the most commonly employed. Test kits will be most sensitive to the PAH from which the antibody was... 

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