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Updated: Dec 13, 2025
Absolute Quantification of Aβ1-42 in CSF Using a Mass Spectrometric Reference Measurement Procedure
Published on: March 21, 2017
First amyloid β1-42 certified reference material for re-calibrating commercial immunoassays
Sébastien Boulo1, Julia Kuhlmann1, Ulf Andreasson2,3
1European Commission, Joint Research Centre (JRC), Geel, Belgium.
Introduction:
Reference materials based on human cerebrospinal fluid were certified for the mass concentration of amyloid beta (Aβ)1-42 (Aβ42 ). They are intended to be used to calibrate diagnostic assays for Aβ42 .
Methods:
The three certified reference materials (CRMs), ERM-DA480/IFCC, ERM-DA481/IFCC and ERM-DA482/IFCC, were prepared at three concentration levels and characterized using isotope dilution mass spectrometry methods. Roche, EUROIMMUN, and Fujirebio used the three CRMs to re-calibrate their immunoassays.
Results:
The certified Aβ42 mass concentrations in ERM-DA480/IFCC, ERM-DA481/IFCC, and ERM-DA482/IFCC are 0.45, 0.72, and 1.22 μg/L, respectively, with expanded uncertainties (k = 2) of 0.07, 0.11, and 0.18 μg/L, respectively. Before re-calibration, a good correlation (Pearson's r > 0.97), yet large biases, were observed between results from different commercial assays. After re-calibration the between-assay bias was reduced to < 5%.
Discussion:
The Aβ42 CRMs can ensure the equivalence of results between methods and across platforms for the measurement of Aβ42 .
