A new fluorescence enhancement solution for europium-based time-resolved fluoroimmunoassays.

A cationic detergent is proposed as suitable insulating agent for the preparation of a fluorescence enhancement solution useful for europium-based time-resolved fluoroimmunoassays. Luminescence from europium ions at concentration as low as 0.5 pmol/l can be detected in solution containing 1.6 mmol/l thenoyltrifluoroacetone, 110.5 mumol/l Adogen 464 and 0.1% Tween 20, in the presence of 0.5 mol/l NaCl. A competitive TR-FIA for rabbit IgG is described, showing that the new enhancement solution allows a sensitivity comparable to that of the high performance LKB Wallac DELFIA.