Yang, TingO’Malley, Tiernan TKanmert, DanielJerecic, JasnaZieske, Lynn RZetterberg, HenrikHyman, BradleyWalsh, DominicSelkoe, Dennis2015-04-012015Yang, Ting, Tiernan T O’Malley, Daniel Kanmert, Jasna Jerecic, Lynn R Zieske, Henrik Zetterberg, Bradley T Hyman, Dominic M Walsh, and Dennis J Selkoe. 2015. “A highly sensitive novel immunoassay specifically detects low levels of soluble Aβ oligomers in human cerebrospinal fluid.” Alzheimer's Research & Therapy 7 (1): 14. doi:10.1186/s13195-015-0100-y. http://dx.doi.org/10.1186/s13195-015-0100-y.1758-9193http://nrs.harvard.edu/urn-3:HUL.InstRepos:14351242Introduction: Amyloid β-protein oligomers play a key role in Alzheimer’s disease (AD), but well-validated assays that routinely detect them in cerebrospinal fluid (CSF) are just emerging. We sought to confirm and extend a recent study using the Singulex Erenna platform that reported increased mean CSF oligomer levels in AD. Methods: We tested four antibody pairs and chose one pair that was particularly sensitive, using 1C22, our new oligomer-selective monoclonal antibody, for capture. We applied this new assay to extracts of human brain and CSF. Results: A combination of 1C22 for capture and 3D6 for detection yielded an Erenna immunoassay with a lower limit of quantification of approximately 0.15 pg/ml that was highly selective for oligomers over monomers and detected a wide size-range of oligomers. Most CSFs we tested had detectable oligomer levels but with a large overlap between AD and controls and a trend for higher mean levels in mild cognitive impairment (MCI) than controls. Conclusion: Aβ oligomers are detectable in most human CSFs, but AD and controls overlap. MCI CSFs may have a modest elevation in mean value by this assay. Electronic supplementary material The online version of this article (doi:10.1186/s13195-015-0100-y) contains supplementary material, which is available to authorized users.en-USJournal Article2015-04-0110.1186/s13195-015-0100-y