P1‐158: Improvements to Innotest® Htau Ag

Abstract

properties of these proteins and the interference of matrix components make the establishment of reference materials very challenging. As a consequence up to now, the trust in the in commercial assays is limited. Since CSF quality control samples were not broadly available. Methods: A large number of individual CSF samples were pooled to establish 5 samples with different A b 1-42 and Ab 1-40 concentrations. Different compounds were added to the pools before lyophilization. The pools underwent one freeze-thaw cycle before aliquotation (250 ml, polypropylene screw-cap tubes). All aliquots were lyophilized and stored at -20 C. The consistency and homogeneity of the prepared panel was evaluated using three different lot numbers of the assays and analysis in 3 different laboratories by different users. In addition, the performance of the proficiency panel was integrated into a multicenter study and compared to performances of neat CSF or run-validation samples (¼ analyte in buffer). Results: Addition of components do not affect analytical behavior of the CSF sample. Lyophilisation of the samples was successful. Stability was considerably increased by that procedure as analytes showed only 5% CV after one week at 37 C. Neat CSF, with and without the additives, as well as samples from the proficiency panel, showed a very good parallelism (¼ absence of matrix interference in the assays) upon dilution for the three analytes evaluated in the study. The production process did not change the intrinsic characteristics of the CSF samples. Overall variability in a multicenter study for the proficiency panel did not exceed > 10%, including the sum of % CV of intra-run, inter-run, inter-operator, and inter-lab. Conclusions: A panel of 5 stabilized and lyophilized CSF samples with target values covering the whole range of the calibration curve of the A b 1-42 , Ab 1-40 and Total-Tau ELISA. The excellent precision data obtained in a multicenter study make this panel an excellent new tool to verify the quality of the biomarker measurements in research settings, but also for routine labs. In the absence of an international reference standard, this commercially available proficiency panel may significantly increase the trust in the values measured by ELISA of CSF diagnostics.

Cerebrospinal Fluid Biomarkers for the Diagnosis of Alzheimer Disease in South Korea

“…The samples were analyzed using the improved version of the INNOTEST ELISA kit (Fujirebio Diagnostics, Ghent, Belgium), which provides ready-to-use antibody calibrators and run validation controls in place of concentrated standards. 20 – 22 Eight CSF samples were analyzed, including 3 pooled samples, in the initial comparison between the runs. The 3 pooled specimens were then used to monitor additional runs.…”