Patent ID: 6951760

Claim:
A method for detection of an analyte in a test sample comprising the steps of: preparing a lanthanide ion-ligand complex by mixing a lanthanide ion and a ligand, wherein the lanthanide ion is selected from the group consisting of neodymium (III) ion, ytterbium (III) ion (Yb3+) and erbium (III) ion (Er 3+ ), and wherein said ligand is bonded to a sensitizing moiety, which absorbs light in the 400-1000 nm region; labeling a reactant or immunoreactant with the lanthanide ion-ligand complex by contacting the reactant or immunoreactant with the lanthanide ion-ligand complex to form a labeled reactant or immunoreactant; mixing an analyte, a specific binding partner for the analyte, and the labeled reactant or immunoreactant to form a mixture, whereby the analyte will bind with the the specific binding partner for the analyte and with the labeled reactant or immunoreactant; separating the unbonded lanthanide ion ligand complexes: irradiating the mixture with light having a wavelength ranging from 400 nm to 1000 nm; measuring an emitted luminescence from the complexes in said mixture formed by binding of said analyte, said specific binding partner, and said labeled reactant or immunoreactant; and detecting the analyte using said luminescence measurement.