Organiser's Note: The presenter of this talk withheld their permission for video to be published.
Today, Alzheimer's disease (AD) can be diagnosed with certainty only post mortem based on the presence of insoluble β-amyloid peptide (Aβ) aggregates and neurofibrillary tangles in the patient's brain tissue. Regarding the amyloid cascade hypothesis, Aβ oligomers and aggregates are directly involved in the pathogenic process. Therefore, presence of Aβ aggregates seem to be the most direct disease biomarker for AD and increasing effort is being made into the development of methods suitable for the detection of different Aβ aggregates in body fluids like CSF and blood.
We developed a method which is able to count single Aβ aggregates from body fluids. The aggregates are captured to a surface, labelled by specific fluorescent probes and detected by scanning the surface with a confocal laser (surface-FIDA) . Here we describe that surface FIDA is sensitive and specific enough to count single Aβ aggregates to be used as a minimally invasive tool for early diagnosis of AD, on line monitoring of disease progression and monitoring of therapeutic approaches. First results show a nice distinction between AD diseased people and non-demented controls by analysing cerebrospinal fluids (CSF) with surface-FIDA [2,3].
 Birkmann E et al.,Vet. Microbiol. 123: 294-304 (2007)
 Funke SA et al., Biochem. Biophys. Res. Commun, 364: 902-907 (2007)
 Funke SA et al., Rejuvenation Res. 11(2):315-318 (2008)