COMPOSITIONS AND KITS FOR FLUORESCENCE POLARIZATION ASSAY OF LARGE MOLECULES

摘要

An improved oligopeptide composition for use in a fluorescent polarization immunoassay for a high molecular weight analyte isdisclosed along with a kit and a method using the composition. The composition comprises an oligopeptide selected by a screeningprocedure in which a plurality of different oligopeptides having respective amino acid sequences that represent sequential overlappingsegments of the analyte amino acid sequence, and a fluorescent label bound thereto. The screening process further includes screening toselect a composition which exhibits fluorescence enhancement upon binding the analyte. A preferred embodiment of the oligopeptide isone having an amino acid sequence which does not form internal disulfide bridges. Such a preferred oligopeptide will generally have nomore than one cysteine residue. In a further preferred embodiment, the fluorescent label is tetramethylrhodamine or a cyanine dye. The kitmay be packaged with instructions directing a user to prepare an assay solution containing the monoclonal antibody and the oligopeptidein certain respective concentrations. The composition, method and kit are constructed to detect nanomolar concentrations of the analyte.