Immunochemical method

There are numerous reports on immunochemical reactions of superoxide dismutases with their respective antibodies The immunochemical evaluation of SOD is 

This example shows that immunochemical methods are not neccessarily highly specific. Cross reactions with immunoprecipitable material or solubilization of antigen complexes can falsify the assay to a considerable extent. Currently more sophisticated techniques bearing a higher specifity than the older methods are employed They are used in many laboratories for routine purposes The most reliable 

Antibodies against CujZn superoxide dismutase are prepared from rabbit antiserum, Purified Cu2Zu2SOD is radioiodinated with I-labeled p-hydroxyliodophenyl- 

A standard curve can be constructed from dilutions of purified superoxide dismutase. The detection Umit is 0.1 ng enzyme. The method is practicable in crude homogenates, like extracts of the red blood cell. The work with radioactive tracers, however, has some disadvantages. If the highly sensitive detection limit is not required, the classical electroimmunoassay can be used. 

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J. M. Van Emon and R. O. Mumma, Immunochemical Methods for Environmental Analysis, ACS Symposium Series 442, American Chemical Society, Washington, D.C., 1990. 

Common Procedures. The general analytical scheme for immunochemical methods is rather simple. The analyte of interest, the antigen (Ag), reacts with the analytical reagent, the corresponding antibody (Ah), forming an immunochemical antigen—antibody complex ... 

Va.ria.tions in Methods. The various immunochemical methods can differ in a number of ways. For example, the analytical reagent may be cmde antisemm, monoclonal antibodies, isolated immunoglobulin fractions, etc. The conditions under which the method is mn, detection of the antigen—antibody complex, and the techniques used to increase sensitivity or specificity of the reaction all maybe varied. 

Iodine is incorporated in thyroid proteins to form thyroxin and 3-I-thyroxine, both hormones essential for life. They are determined by immunochemical methods. Deficiency of I may lead to crop disease. 

N. Haagsma and C. van der Water, Immunochemical methods in the analysis of veterinary drug residues, in Analysis of Antibiotic Drug Residues in Food Products of Animal Origin, ed. V. K. Agarwal, Plenum Press, New York, pp. 81-97 (1992). 

PC. Peng, S.J. Wratten, E.W Logusch, S.R. Horton, and R.C. Sharp, in ACS Symposium Series, Immunochemical Methods in Environmental Analysis, American Chemical Society, Washington, DC, Chapter 15 (1990). 

The concept of immunoassay was first described in 1945 when Landsteiner suggested that antibodies could bind selectively to small molecules (haptens) when they were conjugated to a larger carrier molecule. This hapten-specific concept was explored by Yalow and Berson in the late 1950s, and resulted in an immunoassay that was applied to insulin monitoring in humans. This pioneering work set the stage for the rapid advancement of immunochemical methods for clinical use. 

S.J. Gee, A.D. Lucas, and B.D. Hammock, Using immunochemical methods to analyze for biomarkers of exposure, in Methods of Pesticide Exposure Assessment, ed. PB. Curry,... 

TR. Dombrowski, E.M. Thurman, and G.B. Mohrman, A first application of enzyme-linked immunosorbent assay for screening cyclodiene insecticides in ground water, in Environmental Immunochemical Methods, ed. J.M. Van Emon, C.L. Ger-lach, and J.C. Johnson, American Chemical Society, Washington, DC, pp. 148-154 (1996). 

Van Emon, J. M. Immunochemical Methods of Environmental Analysis. Washington, DC American Chemical Society, 1989. 

Skaare, J.U., E.G. Jensen, A. Goksoyr, and E. Egaas. 1991. Response of xenobiotic metabolizing enzymes of rainbow trout (Oncorhynchus mykiss) to the mono -ortho substituted polychlorinated PCB congener 2,3,4,4,5-pentachlorobiphenyl, PCB-118, detected by enzyme activities and immunochemical methods. Arch. Environ. Contam. Toxicol. 20 349-352. 

Immunochemical methods are valuable because of their sensitivity and specificity. The sensitivity depends on the method used to determine an end point. One of the reaction components may be tagged with radioactivity, or tagged by covalent binding of an enzyme capable of being detected, or by covalent binding of a totally unrelated species (i.e., fluorescein). 

Abstract A significant number of immunochemical methods have been described for the determination of the most important emerging pollutants. The present chapter is a compilation of the information available today regarding immunochemical determination of industrial residues with a high potential risk of causing negative effects in the environment, wildlife, and public health. Homogeneous immunoassays, ELISAs, FIIAs, immunosensors, and selective immunoaffinity sample treatment methods have been reported for the analysis of an important number of these substances. The bases of these methods are briefly presented. 

Although several immunochemical methods have been reported for LAS, few examples of their application to real environmental matrices have appeared. The first immunochemical method for LAS was reported by Fujita et al. [151]. It is a direct ELISA and uses MAbs generated against 5-sulfophenyl valeric acid conjugated to BSA through the carboxylic acid, thus preserving the sulfonic group... 

Immunochemical methods have been reported for both APEs and their metabolites, especially APs. A discussion of the immunochemical methodologies reported to date, the effect of the immunizing haptens employed, and the features of these techniques were recently reviewed [169]. Unfortunately, the detectability achieved is usually far from what is necessary for direct application to environmental samples. Moreover, the selectivity for APs versus APEs is not always satisfactory. Thus, Goda et al. [ 148] developed a direct ELISA for NP with a LOD of 10 pg L 1 and a working range between 70 and 1,000 pg L, but APEs with one to ten ethoxylate units are also well recognized. 

Several attempts have been made to set up immunochemical techniques for dioxin analysis (reviewed in [230,238,239]). Frequently the detectability and selectivity accomplished have not been considered appropriate for the direct analysis of environmental samples. We should notice that due to the poor solubility of PCDDs and PCDFs in water, the levels of these contaminants in aqueous samples is very low. For this reason analysts usually prefer the use of chromatographic and spectrometric methods that perform using organic solvents. However, the speed and high sample throughput that can be accomplished with the immunochemical methods have prompted several research groups and companies to establish immunochemical methods. 

Table 6 Immunochemical methods developed for the detection and quantification of BPA and phthalate esters... 

Several qualitative and quantitative immunochemical methods for CAP analysis in biological matrices of animal origin have been described [101,102, 104,105] (see Table 3). Van de Water et al. [ 102] described an ELISA that detected CAP in swine muscle tissue with an IC50 value of 3 ng mL1. This immunoassay was improved and subsequently optimized incorporating the streptavidin-biotin amplification system. There are also several commercially available test kits (see Table 4). RIDASCREEN is a competitive enzyme immunoassay for the quantitative analysis of CAP residues in milk, eggs, and meat in a microtiter plate. The measurement is made photometrically, obtaining a LOD of 100 ng L 1 in meat and eggs and 150 ng L 1 in milk. The test has been also applied to the analysis of tetracyclines. 

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