title: Utilization of a multiple antigenic peptide as a calibration standard in the BAN50 single antibody sandwich ELISA for Aβ oligomers.
abstract: Soluble amyloid-β (Aβ) oligomers are thought to be a cause of neurodegeneration and memory loss in Alzheimer disease (AD). We recently reported a newly developed enzyme linked immunosorbent assay (ELISA) for high molecular weight (HMW) Aβ oligomers in which the same Aβ monoclonal antibody, BAN50, was used for both capture and detection in a single antibody sandwich ELISA (SAS-ELISA) system. Our previous data suggest that this assay will be useful for the early diagnosis of AD, but its practical application to large-scale or longitudinal studies has been limited because of lack of a reliable calibration standard. In order to develop such a standard, we have now constructed a novel peptide using the multiple antigenic peptide (MAP) technique, where multiple epitopes of BAN50 were linked, via a spacer, to a branching lysine core. We show that the standard curve constructed from a 16-mer MAP covered the physiological range of signals obtained in the BAN50 SAS-ELISA from samples of human CSF, serum, and plasma. Furthermore, this 16-mer MAP is available in large quantities and is stable against freeze-thawing. We estimate that the signal per 1 pM of this standard corresponds to 1.54-5.0 pM of HMW Aβ oligomers. This MAP approach could also be used to provide an effective calibration standard for other SAS-ELISAs.
authors.affiliation: Department of Neurology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto 602-0841, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Kasai
authors.forename: Takahiko
authors.initials: T
authors.lastname: Tokuda
authors.forename: Mark
authors.initials: M
authors.lastname: Taylor
authors.forename: Masanori
authors.initials: M
authors.lastname: Nakagawa
authors.forename: David
authors.initials: D
authors.lastname: Allsop
mesh_terms: D000544:Alzheimer Disease / Q000175:diagnosis*; D000595:Amino Acid Sequence; D016229:Amyloid beta-Peptides / Q000032:analysis* / Q000276:immunology; D000911:Antibodies, Monoclonal / Q000276:immunology; D000941:Antigens / Q000276:immunology; D002138:Calibration; D004797:Enzyme-Linked Immunosorbent Assay / Q000592:standards*; D006801:Humans; D008163:Luminescent Measurements; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000276:immunology
chemical_list: D016229:Amyloid beta-Peptides; D000911:Antibodies, Monoclonal; D000941:Antigens; D010446:Peptide Fragments