Fig. 3
From: Towards a unified protocol for handling of CSF before β-amyloid measurements
Mixing of CSF before Aβ measurements. Aβ42EI (a), Aβ40EI (b), Aβ42/Aβ40EI (c), Aβ42MSD (d), Aβ40MSD (e), and Aβ42/Aβ40MSD (f) in CSF samples that were not mixed before Aβ measurements after being stored at either RT or 4 °C for up to 1 week after collection (6 patients, 4 CSF tubes per patient). Data are shown as the percentage of biomarker levels in CSF samples (from the same donor) that were mixed for 15 min using a roller mixer immediately before the analysis and treated the same way with respect to other experimental conditions (temperature and time). The gray areas represent 95–105% and 90–110% ranges for the EI and MSD assays, respectively, that were set based on the inter-assay CVs as described in the “Materials and methods” section. All biomarker levels in unmixed CSF samples were within 95–105% range of the mixed samples at both temperature and all time points and, therefore, were not tested in the statistical analysis. Horizontal lines and error bars represent mean ± SEM. Abbreviations: Aβ, β-amyloid; BL, baseline; EI, EUROIMMUN; h, hours; MSD, Mesoscale discovery; RT, room temperature; SEM, standard error of mean