Properties of antibodies

3 Molecular components of the immune system 1.3.1 Properties of antibodies 

Neutrophils and host defence The fight against infection 

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Kunneman, D., Rowold, E. and Voliva, C. F. Recognition properties of antibodies to PAMAM dendrimers and their use in immune detection of dendrimers. Manuscript in preparation. 

The aim of this chapter is to discuss fluorescence concepts that are used in selected immunoassay applications. The primary focus is on fluorescence topics of recent interest that provide insight into the characteristic properties of antibodies and antigens in immunoassays, or that describe enhancements in immunoassay technologies. The basic reagents and instrumentation required for immunoassay purposes are discussed first, followed by a brief description of immunoassay formats. The principles that are utilized in various fluorescence immunoassay technologies are outlined with specific examples and their significance. Since it is beyond the scope of this chapter to review all of the applications of fluorescence immunoassays, apologies are extended to authors that this chapter fails to cite. A number of comprehensive treatments of fluorescence immunoassay (FIA) applications and related topics are available. 18 ... 

Fluorescence immunoassays require labeling of antibodies, antigens, or both. The structure and some of the properties of antibodies that are important to the construction of immunoassays are briefly discussed first in this section, followed by a general discussion of probes and some of their characteristics. 

Thorpe, P E and Ross, W. C J (1982) The preparation and cytotoxic properties of antibody-toxin conjugates. Immunol Rev 62, 119-158... 

McMahon, M. J., and O Kennedy, R. 2000. Polyreactivity as an acquired artifact, rather than a physiologic property, of antibodies Evidence that monoreactive antibodies may gain the ability to bind to multiple antigens after exposure to low pH. J. Immunol. Methods 247 1-10. 

Pouget J-P, Ravanat J-L, DoukiT, Richard M-J, Cadet J (1999) Use of the comet assay to measure DNA damage in cells exposed to photosensitizers and gamma radiation. J Chim Phys 96 143-146 Rajagopalan R, Melamede RJ, Laspia MF, Erlanger BF, Wallace SS (1984) Properties of antibodies to thymine glycol, a product of the radiolysis of DNA. Radiat Res 97 499-510... 

Berken A, Benacerraf B. Properties of antibodies cytophilic for macrophages. Journal of Experimental Medicine 1966, 123, 119-144. 

As part of SW-846, the EPA has validated and approved many immunoassay and colorimetric screening methods for a wide range of contaminants, such as petroleum fuels, pesticides, herbicides, PCBs, and explosives. Immunoassay technology uses the property of antibodies to bind to specific classes of environmental pollutants allowing fast and sensitive semiquantitative or qualitative detection. Colorimetric kits are based on the use of chemical reactions that indicate the presence of target analytes by a change in color. Table 3.9 presents a summary of EPA-approved screening methods and their detection capabilities. 

TABLE I Molecular Properties of Antibodies and Related Solid-Phase Separation Methods... 

Main properties of antibodies Related chromatographic separation Type of interaction on solid phase... 

Properties of antibodies Involved ligand Type of affinity separation... 

Immunoassays derive their imique characteristics from two important properties of antibodies the strength of the antibody-antigen binding force and the narrow selectivity within a class of compoimds, sometimes even with absolute specificity for the analyte they were designed for. These two properties allow selective measurement of very low concentrations of analyte even in very complex matrices (e.g., biological fluids, residual waters, etc.). For clarity of presentation, the main terms and concepts used in immunoassays are listed in Glossary . 

Immunoassay methods exploit the selective recognition and binding properties of antibodies for the recognition and quantitation of antigens or haptens. 

Biological Affinity properties of antibodies (kinetic association and dissociation constants, binding constant) 123... 

Fig. 6. Characterization of kinetic properties of antibodies. First, the background signal is recorded using the PZ sensor with immobilized antibody (1) in the carrier buffer only. The association reaction follows in the presence of the sample containing antigen - formation of immunocomplexes at the sensing surface (2), resulting eventually in equilibrium (3). Next, a spontaneous dissociation of the immunocomplexes (4) is observed in the absence of the sample and eventually all immunocomplexes become dissociated (5).

While some challenges have heen largely solved, others remain. Over the next decade it is hkely that additional improvements in the molecular properties of antibodies will be made, further increasing their importance as hiopharmaceuticals. 

Immunocytochemistry takes advantage of three properties of antibodies ... 

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