| 摘要 |
The present invention provides a method of conducting an assay for the detection of a target analyte with enhanced sensitivity, dynamic range, detection limit, selectivity and accuracy using a sandwich assay format. A liquid sample is first brought into contact with a solid phase, where the solid phase is coated with receptors that have a high affinity for an analyte that may be present in the sample. After an incubation period in which the analyt e binds to the receptors, and is thereby immobilized onto the solid phase, a colloidal solution of dye particles is introduced. The dye particles are coated with a second type of receptor that also has a high affinity for the analyte , but a low affinity for the first receptor and also a low affinity for the solid phase. The dye particles therefore bind to the analyte and become immobilized on to the solid phase. The solid phase is then separated from the liquid phase, which in turn separates the bound dye particles from the unbound dye particles. A solubilization buffer, maintained at an appropriate pH, is then added to solubilize the bound dye particles, creating a dye solution. The fluorescence of the resulting dye solution is measured, wherein the solubilized dye molecules strongly absorb excitation light and emit light wi th high efficiency, and theconcentration of the analyte is determined using a pre-determined standard curve.
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