title: A mixed-phase immunoassay based on simultaneous binding of fluorescently tagged and PNA-conjugated peptide epitopes on antibodies: quantification on PNA-coated microparticles.
abstract: A mixed-phase immunoassay based on simultaneous binding of an antibody to its fluorescently tagged peptide epitope and a PNA conjugate of the same peptide has been developed. As a fluorescent marker, a europium(III) chelate allowing time-resolved measurement from a single particle has been employed. The ternary complex formed in solution is immobilized by Watson-Crick base-pairing to a microparticle bearing a PNA sequence complementary to that present in the complex. The concentration of the antibody in the sample may then be determined by a single particle measurement. Accordingly, different antibodies may in principle be addressed by sequence-specific hybridization to different categorized microparticles.
authors.affiliation: Department of Chemistry, University of Turku, FIN-20014 Turku, Finland. kaisa.ketomaki@utu.fi
authors.forename: Kaisa
authors.initials: K
authors.lastname: Ketomäki
authors.forename: Harri
authors.initials: H
authors.lastname: Lönnberg
mesh_terms: D000595:Amino Acid Sequence; D000906:Antibodies / Q000737:chemistry / Q000378:metabolism*; D000939:Epitopes / Q000378:metabolism*; D005456:Fluorescent Dyes / Q000378:metabolism*; D007118:Immunoassay / Q000379:methods*; D008969:Molecular Sequence Data; D020135:Peptide Nucleic Acids / Q000378:metabolism*
chemical_list: D000906:Antibodies; D000939:Epitopes; D005456:Fluorescent Dyes; D020135:Peptide Nucleic Acids