EP0154734A1 — Immediate ligand detection assay, a test kit and its formation

USPTO Abstract

A test kit and safe but rapid assay for detecting the presence of minute amounts of an organic reactant in a test sample includes a plurality of beads or other types of support structures that are impregnated with a fluorescer and coated with a ligand that specifically binds to the organic reactant being investigated. The beads are placed in an aqueous solution, together with the reactant which has been radiolabeled. The portion of the radiolabeled reactant that binds to the ligand is thereby brought in close enough proximity to the beads to activate the fluorescer to produce light energy. The radiolabeled reactant that does not bind to the ligand is, for the most part, disposed too far away from the beads to enable the radioactive energy emitted thereby to reach the fluorescer integrated into the beads. Thus, the level of light energy produced by the fluorescer is indicative of the amount of reactant present in the test sample. The Invention thus avoids the complexities and dangers of prior assay systems.