Date: 19 Apr 2014 (Latest version)

Receptors: Binding Assays

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Synonyms

Labeled ligand binding assays; Ligand binding assays; Radioligand binding assays

Definition

Receptor binding refers to a technique in which a labeled compound, a ligand, which binds to a receptor is used to detect that receptor. Usually, the ligand is labeled by means of a radioactive isotope, such as 3H, 125I, 35S, etc., but a fluorescent moiety is also possible. The receptor can be localized in a tissue that is homogenized or sliced or in cells in culture that either have an endogenous expression of the receptor or have been transfected with a cloned receptor gene. Tissue preparations are incubated with a labeled ligand that has a high binding affinity for the target receptor. The labeled ligand bound to tissue is then collected and detected using various techniques, such as filtration techniques combined with radioactivity counting, scintillation proximity analysis and autoradiography for radioactive ligands, and time-resolved fluorescence resonance energy transfer (TR-FRET) o ...