Initiation of luminol-based luminescence by injection of a single reagent, coupled with enhancement of light-output.

We describe the development of a single-reagent addition to initiate the light output in the oxidation of 6-(N-(4-aminobutyl-N-ethyl)isoluminol) hemisuccinamide (ABEI-H) as the final step in solid-phase luminescence immunoassays. Up until now, the disadvantage of luminol-based luminescence was the need to inject three solutions to optimise stability and performance in immunoassays. By combining these reagents, (pseudoperoxidase, sodium hydroxide and hydrogen peroxide), it has become possible to develop a system which is stable over several hours, and which, almost as a "spin-off" product, has a light-output between 2 and 5-fold that of the original system at the same time hardly altering the reagent blank. Such a system has the advantage that it can be easily adapted to automatic closed systems when these become available for luminescence immunoassays. With this implementation, single-injection light-initiation reactions are not restricted to acridinium-ester or fluorescein isothiocyanate luminescence.