Biospecific multianalyte assay method with labelled microparticles

Claim 1

Biospecific multianalyte assay method, characterized by preparing categories of microspheres representing different analytes to be assayed, said categories comprising different amounts of a fluorescent substance having a short decay time, coating each category of microspheres with a biospecific reactant, pooling the different categories of microspheres together in a suspension, adding a sample containing analytes to be assayed to the suspension, adding a mixture of biospecific reactants labelled with a fluorescent compound having a long decay time to the suspension to initiate biospecific reactions between the analytes and the labelled reactants and microsphere-­associated reactants, diluting the suspension to reduce the concentration of labelled reactants not bound to the microspheres, exciting both the fluorescent substance having a short decay time and the fluorescent compound having a long decay time, associated with the microspheres, to generate fluorescence emissions, converting the fluorescence emissions to electrical signals, identifying the category of each microsphere on the basis of the strength of the electrical signal resulting from the short decay time fluorescent substance, measuring the concentration of the analyte on each microsphere on the basis of the strength of the electrical signal resulting from the long decay time fluorescent compound.