The technical performance of immunological assays and their suitability for the intended use should be carefully validated before implementation in research, clinical studies or routine. We describe here the evaluation of a sandwich electrochemiluminescence immunoassay for measuring total Amyloid-β levels in human blood plasma as an example of a laboratory protocol for a partial "fit for purpose" assay performance validation. We tested two different assay protocols and addressed impact of sample dilution, parallelism, intra- and inter-assay variance, lower limit of quantification, lower limit of detection, and analytical spike recoveries.
Keywords: Alzheimer’s disease; Amyloid-β peptide; Assay validation; Biomarker; Immunoassay.