Immunoanalytical methods

Nowadays, antibodies are utilized in numerous immunoanalytical methods. Those widely used in practice, such as radioimmunoassays, fluoroimmunoassays and enzyme-linked immunosorbent assays (ELISA), require labelled reagents. Millions of ELISA tests for diagnostics of various diseases are daily performed in clinical laboratories. The detection of analytes by two-antibody "sandwich" ELISA, is schematically outlined in Figure 3. 

The continuous monitoring of the analyte concentration is one of the most attractive applications of sensors which cannot be substituted with any other immunoanalytical methods. Biorecognition layers allowing the... 

The application of the term proteomics [13,14], and the development of new HTS laboratory techniques (e.g., immunoanalytical methods, flow cytometry, microarray technologies, and mass spectrometry) open new opportunities in diagnostics. It should be noted that during proteome analysis, (1) there are many differences between the protein content and the protein pattern of different cell populations and (2) many factors (e.g., environmental effects, time, activation, and differentiation states) can cause detectable changes in the proteome of an individual cell. 

Immunoanalytical methods occupy an important position in bioanalytical chemistry. Chemical derivatization plays a fundamental role in this technique. Small analyte molecules (haptenes) are covalently bound to proteins to raise the antibody, which is the basis for their highly selective and sensitive assay. Various labeled derivatives of the analyte are then prepared for competitive binding on the antibody (radiolabeling, labeling for enzyme immunoassay, fluorescence immunoassay, fluorescence polarization immunoassay, and luminescence immunoassay). These derivatization reactions are carried out by the... 

Electrophoretic separation is preceded by adjustment of the sample, usually by enzymatic cleaving with neuraminidase. Separation can be further combined with use of lectin, or with thermoinactivation. Excellent analytical selectivity of the method can be achieved by electrophoretic separation, but for routine use it provides only barely reproducible results in connection with its analytical robustness. An example of a successful application of the electrophoretic separation of BALP as a bone marker are the studies of VanHoof (V3). Currently, the need for an immunoanalytical measuring as a method of choice clearly dominates. 

The properties of high specificity and a wide applicability with many analytes have led to the widespread use of immunoanalytical techniques. The benefits of electrochemical sensors include technical simplicity, speed, and convenience via direct transduction to electronic equipment. Combining these two systems offers the possibility of a convenient assay technique with high selectivity. Because of the complexity of immunoassay methods, such devices have not yet found widespread use. Nevertheless, electrochemical immuno-sensors offer the potential for fast, simple, cost-effective analysis of many... 

---