System for simultaneously conducting multiple ligand binding assays

Abstract

A system for simultaneously conducting multiple ligand assays on a sample potentially containing target analytes uses as a detector a waveguide having a planar surface with a plurality of probes of known recognition to the target analytes thereon. The probes are in discrete areas on the waveguide. A sample containing target analyte is treated with a light-responsive compound such that it binds to the target analyte to form a conjugate and the conjugate is applied to the probes on the waveguide. A laser light is passed into the planar surface of the waveguide at a plurality of different locations, by causing relative movement between the waveguide and the laser light, so that evanescent waves radiate from the waveguide. Where conjugate has attached to a probe, there is emission of light different from that emitted by a probe without conjugate attached thereto.