COVALENT IMMOBILIZATION OF OLIGONUCLEOTIDES TO MICROPARTICLES - QUANTITATION OF HYBRIDIZATION BY TIME-RESOLVED FLUORESCENCE DETECTION ON A SINGLE-PARTICLE

A mixture of microscopic particles, each bearing a given allele-specif ic oligonucleotide probe and a reporter group defining the particle ca tegory, enables simultaneous detection of several gene mutations, prov iding that each particle may be separately subjected to measurement. I t has been shown(1) that a highly sensitive miniaturized assay format may be developed by using uniformly sized (50 mu m) polymethacrylate p articles as a solid phase, and a photoluminescent europium chelate for detection. We now report on alternative ways of tethering the oligonu cleotide probe to the microparticles, and discuss the effects of vario us linkers on the hybridization properties.