BASELINE, YR1, YR2 and YR3 plasma samples (“adni_upennplasma_*.csv”) were assayed in the Biomarker core laboratory using Innogenetics research use only AlzBia reagents on a Luminex immunoassay platform. Plasma Ab1-42/1-40 batch testing immunoassay was performed on 2,454 plasma samples collected from 733 ADNI subjects July 28, 2010 through October 27, 2010 in a total of 76 analytical runs.
Prior to performance of this batch testing the ADNI Biomarker core helped to organize and participated in a 12 center interlaboratory study of the within- and between-center precision of this immunoassay. A report of the latter is available on the ADNI website, and a report on the quality control performance of this test system during the time period of this study of ADNI plasma samples is in preparation and will be uploaded on the ADNI website within the next two weeks.
Missing data are due to the analysis not meeting one of the following analysis criteria used by the ADNI biomarker core for this study: Either %CV between replicates above 20%, low bead COUNTS (less than 20), or MFI below the lowest standard. Quality control samples were EDTA plasma from single individuals whose plasma was aliquoted and stored at -80 0C until the day of assay. Aqueous kit quality control samples were included in each analytical run as well. In addition a total of 195 plasma samples were randomly selected and a never before thawed second aliquot of the plasma sample was re-assayed in a subsequent analytical run.
If you have an ADNI account, you will find the immunoassay data set contained in the “upennplasma” dataset within the adcs_summary.zip file.More Biomarker Core News