Patent ID: 7781227

Claim:
A method of measuring a plurality of analytes in a sample comprising: a) contacting a sample with an array of populations of microparticles, comprising i) a plurality of sets, wherein each set contains a plurality of populations of microparticles, wherein microparticle populations within a set are labeled with different levels of a single fluorophore such that each population exhibits a measurably distinct fluorescence intensity; wherein microparticles in different sets are labeled with different fluorophores; wherein all of said fluorophores have overlapping emission spectra and emit light that is detectable using a single pair of detection channels, and the relative emission in each of the two detection channels is distinguishably distinct between different fluorophores; wherein each of said microparticle populations is distinguishable by its fluorescence emissions in said pair of detection channels; and wherein said array comprises at least 3 sets of microparticle populations; and ii) a plurality of analyte-specific reagents, wherein reagents of the same specificity are coupled to microparticles in the same population, and reagents of different specificity are coupled to microparticles in different populations; for a time sufficient to allow for the formation of microparticle-analyte complexes; b) exposing said microparticle-analyte complexes to excitation light; c) measuring fluorescence of each of said microparticle-analyte complexes in each of said pair of detector channels; d) identifying the specificity of said analyte-specific reagents coupled to said microparticles, thereby identifying the analyte present in each of said microparticle-analyte complexes; e) measuring the amount of analyte present in each of said microparticle-analyte complexes, to provide a measure of the plurality of analytes present in said sample.