The ADNI Biomarker Core has completed the analyses of the CSF biomarkers Ab1-42, t-tau and p-tau181 in pristine aliquots of all 2,401 ADNI1, ADNIGO and ADNI2 CSF samples using the validated and highly automated Roche Elecsys® electrochemiluminescence immunoassays using the same reagent lot for each of these 3 biomarkers. This dataset is now available on the LONI/ADNI website as “UPENN CSF Biomarkers Elecsys”.   The Methods document for this dataset is in preparation and will be available in the near future. This work follows the plans described in the ADNI3 NIA grant renewal and described at previous ADNI Steering Committee meetings. The Roche Elecsys® electrochemiluminescence immunoassays will be used for analyses of all CSFs collected during ADNI3. Based on experience to date this methodologic advance will promote significantly improved center-to-center performance for testing Ab1-42, t-tau and p-tau181 in CSF and sets the stage for implementation in global clinical studies that will hopefully make use of common cutpoints for these AD biomarkers.