Abstract
A method for simultaneous quantification of amyloid-β1-40, amyloid-β1-42 and amyloid-β oligomers in human plasma is described. The method consists of a combination of immunoprecipitation using specific antibodies against the different forms of amyloid-β, and immobilization of the immunocomplexes to magnetic beads. Addition of fluorescence-labelled antibodies which recognize the specific antibodies to the amyloid-β subsets allows the peptide/associates detection in the sample by flow cytometry. The clinical assay performance was tested using blood samples from Alzheimer disease's patients and control donors. A sensitivity of 70% and a specificity of 81% was achieved.