title: Application of an Amyloid Beta Oligomer Standard in the sFIDA Assay.
abstract: Still, there is need for significant improvements in reliable and accurate diagnosis for Alzheimer's disease (AD) at early stages. It is widely accepted that changes in the concentration and conformation of amyloid-β (Aβ) appear several years before the onset of first symptoms of cognitive impairment in AD patients. Because Aβ oligomers are possibly the major toxic species in AD, they are a promising biomarker candidate for the early diagnosis of the disease. To date, a variety of oligomer-specific assays have been developed, many of them ELISAs. Here, we demonstrate the sFIDA assay, a technology highly specific for Aβ oligomers developed toward single particle sensitivity. By spiking stabilized Aβ oligomers to buffer and to body fluids from control donors, we show that the sFIDA readout correlates with the applied concentration of stabilized oligomers diluted in buffer, cerebrospinal fluid (CSF), and blood plasma over several orders of magnitude. The lower limit of detection was calculated to be 22 fM of stabilized oligomers diluted in PBS, 18 fM in CSF, and 14 fM in blood plasma.
authors: ICS-6 Structural Biochemistry, Forschungszentrum Jülich GmbH Jülich, Germany.
authors: Katja
authors: K
authors: Kühbach
authors: ICS-6 Structural Biochemistry, Forschungszentrum Jülich GmbH Jülich, Germany.
authors: Maren
authors: M
authors: Hülsemann
authors: ICS-6 Structural Biochemistry, Forschungszentrum Jülich GmbH Jülich, Germany.
authors: Yvonne
authors: Y
authors: Herrmann
authors: ICS-6 Structural Biochemistry, Forschungszentrum Jülich GmbH Jülich, Germany.
authors: Kateryna
authors: K
authors: Kravchenko
authors: ICS-6 Structural Biochemistry, Forschungszentrum Jülich GmbH Jülich, Germany.
authors: Andreas
authors: A
authors: Kulawik
authors: ICS-6 Structural Biochemistry, Forschungszentrum Jülich GmbH Jülich, Germany.
authors: Christina
authors: C
authors: Linnartz
authors: ICS-6 Structural Biochemistry, Forschungszentrum Jülich GmbH Jülich, Germany.
authors: Luriano
authors: L
authors: Peters
authors: ICS-6 Structural Biochemistry, Forschungszentrum Jülich GmbH Jülich, Germany.
authors: Kun
authors: K
authors: Wang
authors: ICS-6 Structural Biochemistry, Forschungszentrum Jülich GmbH Jülich, Germany.
authors: Johannes
authors: J
authors: Willbold
authors: ICS-6 Structural Biochemistry, Forschungszentrum Jülich GmbHJülich, Germany; Institut für Physikalische Biologie, Heinrich-Heine-Universität DüsseldorfDüsseldorf, Germany.
authors: Dieter
authors: D
authors: Willbold
authors: ICS-6 Structural Biochemistry, Forschungszentrum Jülich GmbHJülich, Germany; Institut für Physikalische Biologie, Heinrich-Heine-Universität DüsseldorfDüsseldorf, Germany.
authors: Oliver
authors: O
authors: Bannach
keywords: Alzheimer's disease; amyloid-β peptide; diagnostic biomarker; early diagnosis; sFIDA; stabilized oligomers; standard molecule; surface-based fluorescence intensity distribution analysis