Antigen-antibody complexation

Most modem RJAs utilize a competitive assay format (Fig. 2) in which radiolabled antigen, Ag, competes with unlabeled antigen, Ag, in a sample for binding to the antibody. Ah. The free antigens are then separated from the antigen—antibody complexes, and the amount of radioactivity in the... 

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. 

A cascade of proteins of the immune response that can be triggered by antigen-antibody complexes and by the innate immune system (e.g. exposure to microbial polysaccharides) to raise the immune response. Complement proteins can detect and bind to foreign material or immune complexes and label them for phagocytosis. They can also cause inflammation by directly degranulating mast cells and releasing chemokines to recruit other immune cells into the affected area. 

Host-derived (e.g., antigen-antibody complexes, activated complement fragments, inflammatory bile acids, urate crystals, certain androgenic steroid metabolites [e.g., etiocholanolone], certain lymphocyte products)... 

Receptors for Fc fragments of IgGs 1 Bind Fc fragments of IgG molecules Target antigen-antibody complexes to myeloid and lymphoid cells, eliciting phagocytosis and other responses... 

An enhancement of SPR signal intensity was observed by the addition of the antibody to the divalent antigen-antibody complex immobilized onto the surface of the sensor chip, indicating the formation of linear supramolecules. An amplification method of the detection signals for a target molecule has been... 

If antigen, released firm the infective agent, is soluble then antigen-antibody complexes are produced. When antibody is present at a concentration eqnal to or greater... 

Qian, R.L., Mhatre, R., and Krull, I.S., Characterization of antigen-antibody complexes by size-exclusion chromatography coupled with low-angle lightscattering photometry and viscometry, /. Chromatogr. A, 787, 101, 1997. 

III Immune Antigen-antibody complexes 3-8 hours May be caused by peni-... 

The nature of the antigenic determinant has been characterized in a male worker with occupational asthma from nickel [415, 416] the antibody recognized Ni2+ bound at the natural Cu2 + /Ni2+ transport site of human albumin. The interpretation was deduced from metal ion blocking experiments and from the good agreement obtained between the pH dependency of the formation of the Ni2 + -albumin complex and the antigen-antibody complex. It was suggested that the antibody interaction depended on a special structural feature of the interaction of Ni2 + with human serum albumin, and perhaps the ability to form an octahedral complex affords one explanation [417]. 

Two methods are commonly employed in RIAs to separate antigen-antibody complexes. The first, the double-antibody technique, precipitates antigen-antibody complexes out of solution by utilizing a second antibody, which binds to the first... 

The nature of an antigen-antibody complex depends upon the ratio of the antigen to antibody rather than their concentrations BECAUSE... 

The number and size of the immune complexes formed by the reaction of antigen with antibody is dependent on the relative concentrations of the reactants (Figure 7.5). The formation of antigen-antibody complexes may be observed by measuring the apparent absorption of light when incident light is scattered by the complexes or by direct measurement of the scattered light. 

Test + Enzme- + Antibody — Antigen-antibody complexes antigen labelled... 

This assay method (RIPA) is used primarily in research. It is too technically demanding for routine use in clinical laboratories. HIV is cultured in radio-labeled cells, or viral proteins are directly labeled with a radioisotope. The virus is disrupted and then exposed to the test specimen. Specific antigen-antibody complexes are concentrated and isolated by immunoprecipitation. After exten-... 

The classical pathway may be activated immunologically by antigen-antibody complexes and aggregated immunoglobulins, and non-immunologically by a number of chemically diverse substances, including DNA, C-reactive protein. Staphylococcal protein A, trypsin-like enzymes and certain cellular membranes (Table III). 

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