Peptide ligand-based ELISA reagents for antibody detection

Detection of specific antibodies has numerous research, therapeutic and diagnostic applications. Short peptide ligands that bind specifically to antibodies with continuous epitopes can be derived from epitope mapping experiments. Short peptide ligands (mimotopes) specific to antibodies with discontinuous epitopes can be identified by screening complex peptide libraries. In an effort to enhance practical utility of such peptide ligands, we describe here a simple approach to turn such target antibody-specific peptide ligands into specific ELISA detection reagents. We show that a simple addition of biotinylated peptide ligands to commonly available horseradish peroxidase (HRP)-labeled streptavidin (or HRP-anti-biotin antibody), or digoxigenin-labeled peptides to HRP-anti-digoxigenin antibody detection reagents transformed these generic detection reagents into sensitive target antibody-specific reagents. ELISA assays performed using these reagents exhibited excellent analytical properties indicating their practical utility for antibody detection. One generic detection reagent can be readily transformed into many different specific ELISA reagents by a simple mix and match design using an appropriate target-specific peptide ligand. Simplicity of preparation of these ELISA reagents for detecting antibodies should facilitate their practical applications.