Liu H.-C.Chen H.-H.Ho C.-S.Chang J.-F.Lin C.-C.MING-JANG CHIUTA-FU CHENHu C.-J.Yan S.-H.Sun Y.Yang S.-Y.2021-11-112021-11-11202121938253https://www.scopus.com/inward/record.uri?eid=2-s2.0-85114775251&doi=10.1007%2fs40120-021-00280-1&partnerID=40&md5=4ca2d7d562e592cfecbee20f55fb5215https://scholars.lib.ntu.edu.tw/handle/123456789/586638Introduction: Concentrations of plasma biomarkers associated with Alzheimer’s disease have been reported to be as low as several tens of picograms/milliliter (pg/ml). However, in assays measuring these biomarkers, it is likely that repeated measurements are necessary to obtain reliable values. Methods: We performed assays as a single test or as duplicate, quadruplicate, fivefold and tenfold repeated tests, on samples spiked with different concentrations of amyloid β 1–40 (Aβ1–40; 1–1000?pg/ml), Aβ1–42 (1–30,000?pg/ml) and total Tau protein (T-Tau; 0.1–1000?pg/ml), with the aim to to calculate the coefficients of variation (CVs). Results: The results demonstrated common changes in the CVs with changes in the number of tests for a given sample: the CVs decreased with increases in the number of tests from one to ten. All CV values were distributed within the range of 0.35 to 15.5%; as such, the CV values were all lower than the acceptable value of 20%. Conclusion: Based on this study, a single assay of Aβ1–40, Aβ1–42 and T-Tau, respectively, provides reliable results in terms of the measurement of that plasma biomarker. ? 2021, The Author(s).[SDGs]SDG3amyloid beta protein; amyloid beta protein[1-40]; amyloid beta protein[1-42]; biological marker; tau protein; aged; Alzheimer disease; Article; blood sampling; brain size; controlled study; female; Geriatric Depression Scale; hippocampus; human; immunomagnetic separation; major clinical study; male; mathematical model; measurement repeatability; mild cognitive impairment; Mini Mental State Examination; neuropsychological test; plasma; protein blood level; volumejournal article10.1007/s40120-021-00280-12-s2.0-85114775251