Enzyme immunoassays application

Massayeff, R. and Maillini, R. (1975) A sandwich method of enzyme immunoassay. Application to rat and human a-fetoprotein. J. Immunol. Methods 8,223-234. 

Sulfonylureas are not directly amenable to gas chromatography (GC) because of their extremely low volatility and thermal instability. GC has been used in conjunction with diazomethane derivatization, pentafluorobenzyl bromide derivatization, and hydrolysis followed by analysis of the aryl sulfonamides. These approaches have not become widely accepted, owing to poor performance for the entire family of sulfonylureas. Capillary electrophoresis (CE) has been evaluated for water analysis and soil analysis. The low injection volumes required in CE may not yield the required sensitivity for certain applications. Enzyme immunoassay has been reported for chlorsulfuron and triasulfuron, with a limit of detection (LOD) ranging from 20 to 100 ng kg (ppt) in soil and water. 

O Sullivan, M., Gnemmi, E., Morris, D., Chieregatti, G., Simmonds, A., Simmons, M., Bridges, J., and Marks, V. (1979) Comparison of two methods of preparing enzyme—antibody conjugates Application of these conjugates for enzyme immunoassay. Anal. Biochem. 100, 100-108. 

Electrophoretic and isotachoelectrophoretic techniques are gaining in popularity in soil analysis with applications to polyaromatic hydrocarbons, polychlorobiphenyls, tetrahydrothiophene and triazine herbicides, Paraquat and Diquat and growth regulators. Other lesser-used techniques include spectrophotometric methods (five determinants), spectrofluorimetric methods (two determinants), luminescence methods (one determinant), titration methods (one determinant), thin-layer chromatography (five applications), NHR spectroscopy (two applications) and enzymic immunoassays (one determinant). 

Several other UV/Vis-based ee assays have been developed, but their general application in directed evolution remains to be demonstrated 66-70). One of them is a well- designed screening system based on enzyme immunoassays (85). The success of the ee assay depends upon the availability of specific antibodies that are easily raised for almost any chiral product of interest. In a given reaction, two antibodies are needed, one that measures the product concentration and the other that measures the amount of one of the enantiomers. About 1000 ee determinations are possible per day, the precision amounting to + 9% (85). 

Duncanson, P., Wareing, D. R. A., and Jones, O. (2003). Application of an automated immunomagnetic separation-enzyme immunoassay for the detection of Salmonella spp. during an outbreak associated with a retail premises. Lett. Appl. Microbiol. 37,144-148. 

Ishikawa, E., Hashida, S., Tanaka, K., and Kohno, T, Development and applications of ultrasensitive enzyme immunoassays for antigens and antibodies. Clin. Chim. Acta 185, 223—230 (1989). 

L2. Lovgren, U., Kronkvist, K., Backstrom, B., Edholm, L.-E., and Johansson, G., Design of noncompetitive fiow injection enzyme immunoassays for determination of haptens Application to digoxigenin. J. Immunol. Methods 208, 159-168 (1997). 

I. Bronstein, B. Edwards, J.C. Voyta, 1,2-Dioxetanes—novel chemi-luminescent enzyme substrates—applications to immunoassays, J. Chemilum. Biolum. 4 (1989) 99-111. 

Brady J.F., J. Turner, and D.H. Skinner (1995). Application of a triasulfuron enzyme immunoassay to the analysis of incurred residues in soil and water samples. Journal of Agricultural and Food Chemistry 43 2542-2547. 

Ito, K. Nakagawa, K. Murakami, S. Arakawa, H. Maeda, M. Highly sensitive simultaneous bioluminescent measurement of acetate kinase and pyruvate phosphate dikinase activities using a firefly luciferase-luciferin reaction and its application to a tandem bioluminescent enzyme immunoassay. Anal. Sci., 19, 105-109 (2003)... 

The first applications of enzyme immunoassay for animal screening appeared in the early 1990s and concerned mainly urine analysis. Later, an enzyme... 

The immunochemical interaction between the antigen and antibody is very specific. By labeling either the antigen or antibody, the method s sensitivity is increased. The most frequently used labels to increase sensitivity are radionuclides (see Radioisotopes) where the assay process is called radioimmunoassay (RIA), or enzymes where the assay is named enzyme immunoassay (EIA) (see Enzyme applications). 

As mentioned earlier, the immunoassay can be done with a number of procedural modifications and in this instance one must substitute the isotope with another molecule (fluorescent dye, magnetic particle, enzyme) which can be measured and therefore serve as the source of tracer. For our initial studies we have chosen to use the enzyme immunoassay (EIA) system. At the present time the EIA is still in its infancy and although a number of successful EIA s have been developed the method cannot be considered a panacea (34). The future of this assay appears to be very bright and exciting, and there is considerable interest in the application of the EIA to problems in both microbiology and clinical medicine (34). Many of the procedures and protocols are derived from RIA procedures and the EIA, like the RIA, has the potential to be performed in a multitude of procedural variations but, for the purpose of this manuscript we will describe only the system we have chosen for our use. 

Franck, M., V. Kolar, and S.A. Eremin (1995). Enzyme immunoassays for s-triazine herbicides and their application in environmental... 

Since the first report on enzyme immunoassay appeared in 1971 (E5, V2) relevant techniques have been developed and applications are increasing. There are many reports on new coupling agents for preparing conjugates of... 

TBG in dried blood samples on filter paper is stable for at least 1 month when kept dry at room temperature. The mean coefficients of variation are 6.6% (within assay) and 5.9% (between assays). The concentrations of TBG in dried blood samples determined by this method correlated well with those in serum determined by radioimmunoassay (r = 0.95) and by enzyme immunoassay (r = 0.96). This method is applicable for detecting patients with congenital TBG deficiency who do not need to be treated and avoids the false-positive results obtained on neonatal screening with T4. 

An extension of enzyme immunoassay is the enzyme affinity assay applicable to studies of nonimmunological interactions. This is already exemplified by the measurement of hormone using its receptor and by our studies on the interaction of fibronectin with collagen. - Assays of these and similar principles might well become a new area of expression for EIA. 

Enzyme immunoassay is widely used, both in competitive and non-competitive formats, for the bioanalysis of a broad range of low-molecular-weight compounds and macromolecules. Through the use of fluorogenic substrates and amplification systems such as avidin-biotin, the sensitivity of enzyme immunoassay has been developed to equal or exceed that of radioimmunoas-say.f ° The technique has found particularly wide applicability in the determination of new recombinant proteins, in demonstrating antibody responses to macromolecules, and in the measurement of biomarkers of disease, as well as in diagnostic medicine. 

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