Development and Technical Validation of an Immunoassay for the Detection of APP669-711 (Aβ-3-40) in Biological Samples.

ABSTRACT: The ratio of amyloid precursor protein (APP)669-711 (Aβ-3-40)/Aβ1-42 in blood plasma was reported to represent a novel Alzheimer's disease biomarker. Here, we describe the characterization of two antibodies against the N-terminus of Aβ-3-x and the development and "fit-for-purpose" technical validation of a sandwich immunoassay for the measurement of Aβ-3-40. Antibody selectivity was assessed by capillary isoelectric focusing immunoassay, Western blot analysis, and immunohistochemistry. The analytical validation addressed assay range, repeatability, specificity, between-run variability, impact of pre-analytical sample handling procedures, assay interference, and analytical spike recoveries. Blood plasma was analyzed after Aβ immunoprecipitation by a two-step immunoassay procedure. Both mono

SUBMITTER: Klafki HW 

PROVIDER: S-EPMC7555726 | biostudies-literature | 2020 Sep

REPOSITORIES: biostudies-literature