title: Sensitive bioaffinity assays with individual microparticles and time-resolved fluorometry.
abstract: Future immunoassays and nucleic acid hybridization assays will be performed in miniaturized formats that utilize microchips or microparticles. This will require a sensitive detection technology that allows spatial resolution. By using fluorescent europium chelates and time-resolved microfluorometry, one can detect 11,000 europium molecules on individual microparticles. In a miniaturized noncompetitive immunoassay of prostate-specific antigen (PSA), we quantitatively detected 5 ng/L (0.05 amol per particle) of the analyte on an individual microparticle with excellent precision over the whole measurement range (CV <10%). Using a hybridization assay, we also could detect the deltaF508 mutation for cystic fibrosis on individual microparticles. Consequently, fluorescent lanthanide chelate labels and time-resolved microfluorometry qualify as the next generation of technology in this field.
authors.affiliation: Department of Biotechnology, University of Turku, Finland. timo.lovgren@utu.fi
authors.forename: T
authors.initials: T
authors.lastname: Lövgren
authors.forename: P
authors.initials: P
authors.lastname: Heinonen
authors.forename: P
authors.initials: P
authors.lastname: Lehtinen
authors.forename: H
authors.initials: H
authors.lastname: Hakala
authors.forename: J
authors.initials: J
authors.lastname: Heinola
authors.forename: R
authors.initials: R
authors.lastname: Harju
authors.forename: H
authors.initials: H
authors.lastname: Takalo
authors.forename: V M
authors.initials: VM
authors.lastname: Mukkala
authors.forename: R
authors.initials: R
authors.lastname: Schmid
authors.forename: H
authors.initials: H
authors.lastname: Lönnberg
authors.forename: K
authors.initials: K
authors.lastname: Pettersson
authors.forename: A
authors.initials: A
authors.lastname: Iitiä
mesh_terms: D002614:Chelating Agents; D003550:Cystic Fibrosis / Q000235:genetics; D005063:Europium; D006801:Humans; D007118:Immunoassay / Q000592:standards*; D009154:Mutation; D017430:Prostate-Specific Antigen / Q000032:analysis; D012680:Sensitivity and Specificity; D013050:Spectrometry, Fluorescence / Q000379:methods*; D013997:Time Factors
chemical_list: D002614:Chelating Agents; D005063:Europium; D017430:Prostate-Specific Antigen