US 6,632,613 B1 · Compositions and kits for fluorescence polarization assay of large molecules

Abstract

An improved oligopeptide composition for use in a fluorescent polarization immunoassay for a high molecular weight analyte is disclosed, along with a kit and a method using the composition. The composition comprises an oligopeptide selected by a screening procedure in which a plurality of different oligopeptides having respective amino acid sequences that represent sequential overlapping segments of the analyte amino acid sequence, and a fluorescent label bound thereto. In a preferred embodiment, the oligopeptide has an amino acid sequence which does not form internal disulfide bridges. Such a preferred oligopeptide will generally have no more than one cysteine residue. In a further preferred embodiment, the fluorescent label is tetramethylrhodamine or a cyanine dye. The kit may be packaged with instructions directing a user to prepare an assay solution containing the monoclonal antibody and the oligopeptide in certain respective concentrations. The composition, method and kit are preferably constructed to detect nanomolar concentrations of the analyte.

Claims20

Dependent claims

A process for performing a fluorescence polarization immunoassay, said process comprising:

providing a monoclonal antibody having an analyte-binding site which selectively binds an analyte;
providing an oligopeptide tracer comprising an oligopeptide, said oligopeptide having an amino acid sequence which does not form internal disulfide bridges, and which is constructed to selectively bind to the analyte-binding site, and having an N-terminal end, a linker segment of from one to five amino acid residues covalently linked to the N-terminal end of the oligopeptide, and a fluorescent moiety attached to the linker segment contacting the monoclonal antibody with the oligopeptide tracer in a solution and determining a first polarization value of the fluorescent molecule;
providing a sample comprising an unknown quantity of the analyte;
adding the sample to the solution containing the monoclonal antibody and the oligopeptide
tracer and determining a second polarization value of the fluorescent molecule;
and comparing the first and second polarization values to make an estimate of the amount of the analyte in the sample.

3 more elements

Dependencies are inferred from the claim text.

Compositions and kits for fluorescence polarization assay of large molecules

Life of this patent

Compositions and kits for fluorescence polarization assay of large molecules

Life of this patent

Abstract

Claims20