Ligand Displacement Immunoassay

Abstract

Ligand displacement immunoassay (LDI) is an immunoassay that uses an immunocomplex consisting of immobilized antibodies that have been presaturated with labeled analyte ligand, or conversely, it can use a complex of immobilized analyte ligands that are prebound with corresponding labeled antibodies. The complex of antibody–antigens dissociates when it is exposed to analytes. Thus, the labeled reagents are displaced by the analyte in the test sample. This review focuses on three aspects of immunochemistry that are germane to the development of an LDI. The interaction of antibody with antigen, the solid phase and methods used for the immobilization of immuno‐reagents and the labels and labeling methods used in LDI are discussed in details.

Keywords:

• ligands
• immunoassay
• fluorescence
• enzymes
• solid phase