Fig. 4

Correlation of plasma Aβ42/40 measurements after pre-analytical Aβ immunoprecipitation on two different immunoassay platforms. Following magnetic bead immunoprecipitation (IP) from EDTA blood plasma, Aβ42/40 was quantified in diluted IP-eluates with Elecsys (5-fold dilution) and MSD (6-fold dilution). Data points are colored by diagnostic group (red = Aβ+, blue = Aβ−). The diagonal dashed line corresponds to the identity line. Aβ, amyloid-β; Aβ+, Aβ-positive: CSF Aβ42/40 ≤ 0.050; Aβ−, Aβ-negative: CSF Aβ42/40 > 0.050; MSD, Meso Scale Discovery V-PLEX Aβ panel 1 (6E10) assay kit