Novel biotinylated acridinium derivatives: new reagents for fluorescence immunoassays and proteomics

The favorable properties of acridinium derivatives over conventional fluorescent probes have attracted considerable interest. These conjugates have found wide utility in tests developed for medical diagnosis providing at least comparable sensitivity to radioimmunoassay (RIA) and enzyme immunoassay (EIA) procedures.

In this paper we describe the synthesis, luminescent properties and immunoassay applications of two novel biotinylated acridinium derivatives, 9-(2-biotinyl-oxyethyl)-carboxylate-10-methyl-acridinium triflate, BOCMAT and 9-(2-biotinyl-amidoethyl)-carboxylate-10-methyl-acridinium triflate, BACMAT.

The chemiluminescence efficiency of the novel reagents is high in polar aprotic solvents and attains detection limits down to 7.28 x 10(-8) M, while the fluorescence efficiency has its maximum in aqueous solutions with detection limits down to 1.94 x 10(-10) M. The above novel compounds were applied in the fluorimetric determination of solid phase-immobilized biotinylated mouse IgG and the detection limit was found to be approximately 1 microg/assay ( approximately 7 pmol/assay).

The new streptavidin-based detection reagents were synthesized can be used for the development of highly sensitive solid-phase fluorescence-based immunoassays and may find important applications in proteomics.