title: Immuno-PCR-based quantification of multiple phosphorylated tau-epitopes linked to Alzheimer's disease.
abstract: Several lines of evidence suggest that quantification of phosphorylated sites in the tau-protein (phospho-tau) might be favorable for early and specific Alzheimer's disease diagnosis. The typical setup to quantify phosphorylated tau-epitopes relies on a sandwich ELISA with a capture antibody (Ab) recognizing tau independent of its phosphorylation status and a detector Ab binding specifically to a certain phosphorylation site. Besides Ab specificities, major challenges arise from the very low tau-concentrations in cerebrospinal fluid (CSF) ranging from 100 to 2,000 pg/ml. Based on the phosphorylation degree of a given position, which can be below 10%, the corresponding phospho-tau-level might be much lower, especially for multiphosphorylated epitopes studied here. Thus, a novel, highly sensitive, and generally applicable immunoassay is described to quantify tau-versions, which are phosphorylated at pThr212/pSer214/pThr231/pSer235, down to tau-concentrations of 2 pg/ml in CSF.
authors.affiliation: Institute of Bioanalytical Chemistry, Center for Biotechnology and Biomedicine, Faculty of Chemistry and Mineralogy, Leipzig University, Deutscher Platz 5, 04103 Leipzig, Germany.
authors.forename: David
authors.initials: D
authors.lastname: Singer
authors.forename: Hilkka
authors.initials: H
authors.lastname: Soininen
authors.forename: Irina
authors.initials: I
authors.lastname: Alafuzoff
authors.forename: Ralf
authors.initials: R
authors.lastname: Hoffmann
mesh_terms: D000544:Alzheimer Disease / Q000134:cerebrospinal fluid / Q000378:metabolism*; D000906:Antibodies; D015415:Biomarkers; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D000939:Epitopes; D006801:Humans; D010766:Phosphorylation; D016133:Polymerase Chain Reaction / Q000379:methods*; D016875:tau Proteins / Q000134:cerebrospinal fluid / Q000378:metabolism*
chemical_list: D000906:Antibodies; D015415:Biomarkers; D000939:Epitopes; D016875:tau Proteins