Antibodies immunoassays based

Figure 13 Structures of haptens used for immunizing and coating antigens in a monoclonal antibody-based immunoassay for diuron. A sensitive assay was developed using coating hapten I that had the handle in a position different from the immunogen hapten. When the oxygen in the urea moiety of hapten I was replaced with a sulfur (hapten 11), increasing the heterology, even greater sensitivity was achieved...

The most common use of protein microarrays is in immunoassays. In particular, antibody-based immunoassays are the main stream of diagnostic assays due to their specificity. The assay usually runs in a multiplexed mode where the antibodies or other capture agents are immobilized and then exposed to a biological sample. There are four immunoassay formats direct binding, sandwich (ELISA), competitive, and displacement. Direct-binding and sandwich assays are the most common. There are some reports on the use of competitive assays and displacement assays, which are usually associated with high surface area/volume systems [72-76],... 

Giersch, T., K. Kramer, M.G. Weller, and B. Hock (1993b). Improvement of a monoclonal antibody-based immunoassay for the determination of terbutryn. Acta. Hydrochim. Hydrobiol., 21(6) 312-315. 

Abad, A., M.J. Moreno, and A. Montoya. 1999. Development of monoclonal antibody-based immunoassays to the JV-methylcarbamate pesticide carbofuran. J. Agric. Food Chem. 47 2475-2485. 

The first assay (a radioimmunoassay) that measured cTnl used polyclonal anti-cTnl antibodies. The first monoclonal enzyme-linked immunosorbent assay, anti-cTnl antibody-based immunoassay, was described by Bodor and co-workers (1992). Numerous manufacturers have now developed monoclonal antibody-based diagnostic immunoassays for the measurement of cTnl in serum. Assay times range from 5 to 30 minutes. 

In order to become a viable alternative, MIP-based assays need to offer an added value to the conventional antibody-based immunoassays. Some characteristics of the MIP-based assays are summarised in Table 14.1. Superior characteristics of MIPS in comparison to antibodies are observed with respect to chemical, mechanical and thermal stability. The MIPs are compatible with autoclave conditions (120°C, 20 min) and are unaffected by acid and base treatment [7]. In fact, to achieve as complete removal of imprint molecules as possible, in the author s laboratory it is routine to include a wash step with 5 M sodium hydroxide in the MIP synthesis work-up protocol. The possibility of using a wider range of assay solvents, namely both aqueous and organic solvents, enables the solubility of the analyte to be assured and problems with non-specific adsorption minimised. Furthermore, high polymer stability leads to improved shelf life, where the MIP can be stored for several years in the dry state at ambient temperatures. 

Cummins and co-workers were the first to develop a radioimmunoassay to measure cTnl that used polyclonal anti-cTnl antibodies. Although the assay showed approximately 2% cross-reactivity with skeletal Tnl, it stiU had excellent clinical specificity for cardiac muscle injury. The assay was never automated or developed for commercial use. The first monoclonal ELISA, anti-cTnl antibody-based immunoassay, was described by Bodor et al. This assay has less than 0.1% cross-reactivity with skeletal Tnl, but it was not suited for clinical use because of the lengthy assay time. Over the past 15 years, numerous manufacturers have described the development of monoclonal antibody-based diagnostic immunoassays for the measurement of cTnl in serum. Assay times range from 5 to 30 minutes. As shown in Table 44-1, over a dozen assays have been approved by the FDA for patient testing within the United States on central laboratory and POCT platforms. In addition to these quan-... 

Tracy RP, Andrianorivo A, Riggs BL, Mann KG. Comparison of monoclonal and polyclonal antibody-based immunoassays for osteocalcin a study of sources of variation in assay results. J Bone Miner Res 1990 5 451-61. 

Type I allergens are usually considered those macromolecules with the ability to induce specific IgE immune responses and to provoke allergic reactions in sensitized subjects. Antibody-based immunoassays are widely used for the measurement of specific major allergens in the air. Antibodies can originate from sensitized humans, animals (rabbits producing polyclonal antibodies) or fusions of myeloma cells and mouse spleen cells in culture producing monoclonal antibodies. Examples have been published using... 

Production of antisera does not require specialized immunological techniques and cell culture facilities. Therefore it may be a simpler, faster and cheaper way than production of monoclonal antibodies (see section 3.3.). However, it must be noted that antisera-based immunoassays are sometimes less selective than monoclonal antibody-based immunoassay because of the polyclonality of antibodies in the antisera, and good antisera are not reproduced. The production of high affinity antisera may be helped by long-term immunization schedules from the mechanism of antigen-dependent B lymphocyte differentiation and selection (23). 

Antibody-based immunoassays may become widely accessible and might turn into routine procedures in physiological, biochemical and molecular biological studies on plant secondary metabolites. Future development in this field will provide a detailed knowledge of tissue and organ distribution, intracellular localization and translocation of secondary products. 

E. W. Weiler, J. Eberle, R. Mertens, R. Atzorn, M. Feyerabend, P. S. Jourdan, A. Arnsheidt, U. Wieezorek, in T. L. Wang (Ed.), Immunology in plant science. Antisera-and monoclonal antibody-based immunoassay of plant hormones, Cambridge Univ. Press, 1986, pp. 27-58. 

Foiles, P. G. Chung, F. Hecht, S. S. Development of a monoclonal antibody-based immunoassay for cyclic DNA adducts resulting from exposure to crotonaldehyde. Cancer Res., 47 360-3. 1987. 

Nehls, P. Rajewsky, M. F. Monoclonal antibody-based immunoassay for the determination of cellular enzymatic activity for repair of specific carcinogen-DNA adducts 0-6 alkylguanine. Carcinogenesis (Lond), 11 81-8. 1990. 

Immunoassays are analytical experiments in which identification and quantificatiOTi of target molecules are done by using highly specific antibodies. Antibody-based immunoassays are the most commonly used technique to identify different types of analytes such as proteins, peptides, and low molecular weight molecules. This technique has been used in hospitals, laboratories, and industries for the last few decades to detect antibody-antigen in samples. 

Dewey, F.M., S.E. Ebeler, D.O. Adams, A.C. Noble, and U.M. Meyer. 2000. Quantification of Botrytis in grape juice determined by a monoclonal antibody-based immunoassay. Am.J. Enol. Vitic. 51 276-282. 

The commonly used methods for the determination of these drugs are immunoassays and chromatography. Most immunoassays for immunosuppressants are semiautomated since extraction of drugs from the whole blood is needed before analysis. Immunoassays are convenient due to automation, but have problems with cross-reactivity with drug metabolites (3, 6). Both polyclonal and monoclonal antibody-based assays are available. Monoclonal antibody-based immunoassays are more specific. HPLC with ultraviolet detection and tandem mass spectrometry are commonly used chromatographic methods for the assay of immunosuppressants. Due to their specificity and sensitivity, tandem mass spectrometry assays are preferred and are now in wide use (7, 8). The other major advantage of tandem mass spectrometry assays is their ability to simultaneously measure several immunosuppressants (7-10). Pharmacokinetic properties of CSA, sirolimus, and tacrolimus are shown in Table 1 (3, 6, 11). 

Raybould T, Bignami GS, Inouye LK, Simpson SB, Byrnes JB, Grothaus PG, et al. A monoclonal antibody-based immunoassay for detecting tetrodotoxin in biological samples. J Clin Lab Anal 1992 6 65—72. 

Shone, C., Wilton-Smith, R, Appleton, N., Hambleton, R, Modi, N., Gately, S., and Melling, J., 1985, Monoclonal antibody-based immunoassay for type A Clostridium botulinum toxin is comparable to mouse bioassay. Appl. Environment. Miocrobiol. 50 63-67. 

Gibson, A.M., Modi, N.K., Roberts, T.A., Hambleton, R, and Melling, J., 1988, Evaluation of a monoclonal antibody-based immunoassay for detecting type B Clostridium botulinum toxin produced in pure culture and an inoculated model cured meat system, J. Appl. Bacteriol. 64 285-291. 

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