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Fig. 1 | Alzheimer's Research & Therapy

Fig. 1

From: Towards a unified protocol for handling of CSF before β-amyloid measurements

Fig. 1

CSF storage at RT and 4 °C. Aβ42EI (a), Aβ40EI (b), Aβ42/Aβ40EI (c), Aβ42MSD (d), Aβ40MSD (e), and Aβ42/Aβ40MSD (f) in CSF samples that were stored at either RT or 4 °C for up to 2 weeks after collection (12 patients, 10 CSF tubes per patient). Data are shown as the percentage of biomarker levels in fresh, non-processed, CSF samples (from the same donor) that were analyzed within hours after LP. The effects of pre-analytical factors were tested using the mixed-effects model including participant identification as a random effect and temperature, time, and time × temperature interactions as fixed factors. 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. Only changes in the mean biomarker levels outside these ranges (gray areas) were considered to be due to pre-analytical sample handling and examined using post hoc tests. *p ≤ 0.05, **p ≤ 0.01, ***p ≤ 0.001. Horizontal lines and error bars represent mean ± SEM. Abbreviations: Aβ, β-amyloid; EI, EUROIMMUN; h, hours; MSD, mesoscale discovery; RT, room temperature; SEM, standard error of mean

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