CEDIA (Cloned Enzyme Donor Immunoassay)
Definition
A homogeneous immunoassay using two inactive fragments of beta-galactosidase, an enzyme donor (ED) fragment conjugated to drug, and an enzyme acceptor (EA) fragment. When free (not antibody-bound), ED and EA spontaneously associate to form active enzyme. Sample drug displaces ED conjugate from antibody, allowing association and raising enzyme activity.
Related terms
- Cross-Reactivity
- The capacity of an antibody raised against one analyte to bind structurally related compounds. In RIA, cross-reactivity is the main driver of...
- Cut-Off Concentration
- The threshold analyte concentration, set by regulatory guidance, above which a specimen is reported as a screen-positive. Choosing the cut-off balances sensitivity...
- EMIT (Enzyme-Multiplied Immunoassay Technique)
- A homogeneous competitive immunoassay in which drug in the sample competes with enzyme-labelled drug conjugate for antibody binding sites. Free enzyme-labelled conjugate...
- Lateral-Flow Immunoassay
- A point-of-care competitive immunochromatographic format on a nitrocellulose strip. In the absence of drug, colloidal gold-labelled antibody is captured at a test...
- Post-Mortem Redistribution
- The movement of drugs from solid tissues into central blood after death, due to diffusion along concentration gradients, autolytic enzyme release, and...
Explained in
- Immunological Drug Testing: Screening and Forensic InterpretationA homogeneous immunoassay using two inactive fragments of beta-galactosidase, an enzyme donor (ED) fragment conjugated to drug, and an enzyme acceptor (EA) fra...