Antibody-antigen reactions

A base, formed by the bacterial degradation of histidine, and present in ergot and in many animal tissues, where it is liberated in response to injury and to antigen-antibody reactions. If injected it causes a condition of shock with dilatation of many blood vessels, loss of plasma from the capillaries to the tissues and a rapid fall in blood pressure. It is normally prepared from protein degradation products. 

There are many possible means for quantification of the antigen—antibody reaction. Immunoassays may be classified according to the technology used for detection and quantification of the analyte being detected. 

Turbidimetric Agglutination Immunoassays. Agglutination—precipitation immunoassays were among the first practical appHcations of the antigen—antibody reaction in diagnostic tests. These assays are not as widely used in the 1990s as EIA and FIA because they are either not quantitative enough or lack the sensitivity limits of RIA, EIA, and EIA. 

Not all antigen-antibody reactions are of benefit to the body, as sometimes the complexes (or their subsequent interaction with body tissues) may result in tissue damage. This must be regarded as a malfunction of the immune system and is known as a hypersensitive reaction. These reactions can be categorized into five main types. The first three involve the interaction between antigen and humoral antibody, and as the onset of the reaction is rapid, the condition is termed immediate hypersensitivity. The fourth type (delayed hypersensitivity) involves T cells and the symptoms of the reaction appear after 24 hours. The fifth type is where antibody stimulates cell function. 

Although there is no direct evidence that molecular structure and gelation properties show such a close correlation, this hypothesis may help to show that the mechanism of gelation is a very specific reaction analogous to specific biochemical reactions, like antigen-antibody reactions, etc., in which polysaccharides are also involved. 

Coating the antigen or antibody directly on appropriately modified metal substrates has yielded electrodes that respond potentiometrically to antigen-antibody reactions An immunoelectrode has been prepared by coating the gate of a... 

First described in 1926 by Perrin [16], the theory was greatly expanded by Weber [17], who developed the first instrumentation for the measurement of FP. Dandliker [18] expanded FP into biological systems such as antigen-antibody reactions and hormone-receptor interactions. Jolley [19] developed FP into a commercial system for monitoring of therapeutic drug levels and the detection of drugs of abuse in human body fluids. 

Eosinophil 1 %—4% Antigen-antibody reactions Eosinophilia Hypersensitivity reactions, including medications Parasitic infections... 

Montero C.The antigen-antibody reaction in immunohistochemistry./. Histochem. Cytochem. 2003 51 1-4. 

Moeremans, M., Daneels, G., Van Dijck, A., Langanger, G., and De Mey, J. (1984) Sensitive visualization of antigen-antibody reactions in dot and blot immuno overlay assays with the immunogold and immu-nogold/silver staining./. Immunol. Meth. 74, 353-360. 

M. Vladimir, M. Mirsky, O. Riepl, and O. Wolfbeis, Capacitive monitoring of protein immobilization and antigen—antibody reactions on monomolecular alkylthiol films on gold electrodes. Biosens. Bioelectron. 12, 977-989 (1997). 

Immobilization techniques have been applied in the preparation of immobilized CL reagents, with specific advantages such as reusability, improved stability, and increased efficiency. These strategies have been applied in the development of CL sensors, which today constitute the most important tools in analytical chemistry because of the high sensitivity offered. Optical fibers have been used to transfer light in order to improve the quality of detection, and new types of flow-through cells have been introduced in the construction of CL sensors. Also, selectivity has been considerably improved by the utilization of enzymatic or antigen-antibody reactions. 

In the IV route, anaphylactic reactions (caused by administration of an agent to an animal previously sensitized to it or to a particularly sensitive species such as a guinea pig) may be especially severe, probably because of sudden, massive antigen-antibody reactions. When the drug is given by other routes, its access to antibody molecules is necessarily slower moreover, its further absorption can be retarded or prevented at the first sign of a serious allergic reaction. 

The stereospecificity of antigen-antibody reactions has gained its due recognition more than half-a-century ago. However, an intensive and extensive stereospecificity radioimmunoassay procedures have been adequately applied to a number of pharmaceutical substances since mid-seventies, for instance atropine, propranolol, methadone-to name a few. 

Immunology Antigen—antibody reactions I mmunoas says... 

Figure 7.5 Antigen-antibody reaction. Maximum precipitation occurs when the antigen and antibody are present in equivalent amounts and is due to the formation of large lattice structures. On either side of the equivalence zone the amount of precipitation is reduced because the aggregates are smaller and more soluble.

These techniques are notable for the fact that they rely on the diffusion of only one component of the antigen-antibody reaction in the technique of... 

A partially purified HIV viral lysate is laid onto a sodium dodecyl sulfate (SDS)-polyacrylamide gel slab and then electrophoresed, which distributes the HIV peptides through the gel by their relative molecular mass. The higher-molecular-mass proteins form bands near the top of the gel. The proteins on the gel are then transferred electrophoretically onto nitrocellulose paper. The paper is sliced into thin strips, each having the full distribution of HIV antigen bands. The strip is used as a solid support of an indirect immunoassay, and antigen-antibody reactions form insoluble colored bands on the strip. 

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