Immunochemical methods, advantages

Although both polyclonal and monoclonal antibodies have been effectively used in immunochemical assays, only the latter can provide the high specificity required in some applications. Antibody specificity, on the other hand, is both a major advantage and disadvantage for immunochemical methods. It allows for highly selective detection of analytes but at the same time may complicate the development of multiresidue methods. Moreover, production of monoclonal antibodies requires special expertise and it is much more expensive than polyclonal antibodies. Thus, in cases where a range of analytes similar in molecular structure are required to be determined, a polyclonal may be more suitable than a monoclonal antibody. 

Newsome, W.H. (1986). Potential and advantages of immunochemical methods for analysis of foods. J. Assoc. Off. Anal. Chem., 69 919-923. 

Possible Contributions of Immunochemical Methods to Pesticide Analysis. As Ercegovich (3 ) pointed out, it is unlikely that immunochemical methods will replace current, established analytical methods of pesticide analysis. However, the analytical chemist who carefully compares the attributes and deficiencies of immunochemical methods of analysis with other procedures is likely to find applications for which immunochemical methods offer distinct advantages. 

It is probable that in certain situations immunochemical methods will provide distinct advantages over conventional analytical methods. However, it is unlikely that immunochemical methods will completely replace current, established analytical methods of pesticide analysis (5.). This is in spite of the fact that chemical classes currently assayed by immunochemical techniques in clinical analytical labs contain the same type of functional groups as many pesticides. 

The advantage of iron labeling for electron microscopy has inspired the use of some other metals and iron in the form of other compounds, for instance ferrocene, e.g. bis-pentadienyl iron Mercury uranium and osmium are also widely used in electron microscopy for protein labeling. Because they are easy to detect and because they attach themselves readily to antibodies and antigens, metals are very promising labels in immunochemical methods. Voller forecasts the development of a new generation of simple metaloimmunoassays. 

Immunochemical methods are rapidly gaining acceptance as an option for residue and other environmental analyses. They offer the advantages of being reliable, simple, relatively inexpensive, and field adaptable alternatives to... 

Advantages, Drawbacks and Future of Immunochemical Methods Acknowledgements... 

Specific methods Immunochemical methods have been developed for identification and specific determination of proteins that have no catalytic activity. The method is based on the special relationship between a protein and a specific antibody that has been raised against the protein. The advantages of an immunoassay lie in its high specificity and detectability. Since the specificity is independent of the activity of the antigen protein, the method measures all enzyme molecules, inactive as well as active. The methods depend on the availability of specific antisera directed against the particular enzymes under study. The antibody is raised in an experimental animal by injection of a sample of protein antigen. Selective precipitation method and enzyme linked immunosorbent assay (ELISA) are commonly used for the specific detection and reliable measurement of a particular enzyme in a raw sample, such as a tissue extract or body fluids. 

In the field of food microbiology, immunochemical methods are advantageous with respect to microbiological methods in terms of labor and time, in particular for those species and strains whose isolation and identification call for lengthy and cumbersome procedures. Immunochemical procedures allow cutting down substantially on these requirements, by following different strategies. 

Immunochemical methods for protein analysis were discussed by Taylor (194) and by Kendall (195). This type of method offers considerable advantages when a single protein of a mixture must be determined, because of the high degree of specificity obtainable. It is scarcely possible to consider it as a regular chemical procedure as yet. 

Isotope dilution in combination with the substoichiometric principle is applied in various ways. The most important examples are radioimmunoassay for protein analysis and DNA analysis. In radioimmunoassay, radionuclides are used as tracers and immunochemical reactions for isolation. Radioimmunoassay was first described in 1959 by Yalow and Berson, and since then has found very broad application in clinical medicine, in particular for the measurement of serum proteins, hormones, enzymes, viruses, bacterial antigens, drugs and other substances in blood, other body fluids and tissues. Only one drop of blood is needed, and the analysis can be per-fonned automatically. Today more than 10 immunoassays are made annually in the United States. The most important advantages of the method are the high sensitivity and the high specificity. In favourable cases quantities down to 10 g can... 

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