Emit Elisa Ria

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Emit (Enzyme Multiplied Immunoassay Technique) is:
* cheapest and simplest technique
* an analytical method used in Clinical Toxicology
* commonly used in screening blood (serum) for TDM (Therapeutic Drug Monitoring) and as a primary screening procedure of abused drugs and their metabolines in the urine. * it is the first homogenous assay to be widely used.

* the separation using antibody specificity (antigen binding). * measurement of enzyme-substrate reactions using visible spectroscopy, and standard curve. * produces reliable results
* the test utilizes antibodies that are enzyme linked and react only with the specific substance in the sample(urine or blood) is positive with the particular drug being tested.

Technique
1) Combine a sample containing an unknown concentration of antigen (Ag) & a solution containing a known concentration of antibody against the Ag (Ab). 2) Allow binding of Ag & Ab (incubation #1).
3) Add a known concentration of prepared Ag-enzyme conjugate. 4) Allow binding of Ag-enzyme conjugate with any remaining unbound Ab in solution (incubation #2). The conjugate is constitutionally active; binding to any unbound Ab will render it inactive. 5) Add enzyme substrate.

6) Measure enzyme activity.

Performing an ELISA involves at least one antibody with specificity for a particular antigen. The sample with an unknown amount of antigen is immobilized on a solid support (usually a polystyrene microtiter plate) either non-specifically (via adsorption to the surface) or specifically (via capture by another antibody specific to the same antigen, in a "sandwich" ELISA). After the antigen is immobilized, the detection antibody is added, forming a complex with the antigen. The detection antibody can be covalently linked to an enzyme, or can itself be detected by a secondary antibody that is linked to an enzyme through bioconjugation. Between each step, the plate is typically washed with a mild detergent solution to...
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