Immunoassay reversible binding

Immunoassay methodologies are now a major method for rapid analysis of many mycotoxins, especially aflatoxins. These immunochemical techniques are based upon quite different principles to chromatographic procedures. In essence, immunochemical procedures involve reversible binding between antigens (the... 

Aptamer based biosensors, for example for recombinant human erythropoietin (as model analyte), can be made more sensitive by amplification with a boronic acid tethered gold nanoparticle that is then associated with an alkaline phosphatase to produce a redox active probe molecule. A similar re-usable bio-immuno-sensor has been suggested for carcinoembryonic antigen. A phenylboronic acid is assembled on gold to (reversibly) bind the antibody horseradish peroxidase conjugate. Interaction with the antigen slows down the hydrogen peroxide reduction. An HIV-1 immunoassay based on electroluminescence has been proposed by Zhou etaV In this process the... 

EE Howell, J Nasser, KJ Schray. Coated tube immunoassay Factors affecting sensitivity and effects of reversible protein binding to polystyrene. J Immunoassay 2 205, 1981. 

In fluorescent immunoassay (FIA), a fluorescent molecule is covalently bound to a molecule of analytical interest. The labeled analyte interacts reversibly with an antibody (usually derived from a rabbit or goat) which is specific for the analyte and will bind with about equal affinity to the labeled or unlabeled analyte. The labeled analyte usually shows different fluorescent properties according to whether it is bound by the antibody or free to diffuse in solution. The serial additional of different concentrations of the analyte to the labeled analyte-protein... 

The target molecule may be covalently or noncovalently linked to a functional monomer. Usually, with an increase in binding sites between target molecule and functional monomer, the specific molecular recognition will be increased, but the reversibility of sensor will be decreased. Under certain conditions, we are only interested in specific molecular recognition. For example, we prepared a MIP as an alternative to an antibody in an immunoassay. In this application, the reversibility of MIP is not important. However in other situations, we have to achieve a balance between the specific recognition and reversibility for sensor design. 

EEIA may be realized in different ways. Homogeneous (non-separation) enzyme immunoassay is based on the principle of modulation of activity of the enzyme label when an antigen binds to an antibody. This means that the activity of an enzyme label may be enhanced (activation) or suppressed (inhibition). In the first case, for instance, the attachment of a thyroxine to malate dehydrogenase causes an inhibition of the enzyme. This inhibition is, however, reversed when this conjugate binds... 

Immunoassay is based on the antigen (or hapten)-antibody binding reaction which is both reversible and non-covalent ... 

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