Baker Heart and Diabetes Institute 1 article published in JoVE Biology A Step-By-Step Method to Detect Neutralizing Antibodies Against AAV using a Colorimetric Cell-Based Assay Sebastian Bass-Stringer1,2, Colleen J. Thomas2,3, Clive N. May3, Paul Gregorevic4, Kate L. Weeks1,5,6, Julie R. McMullen1,2,5,6,7 1Baker Heart and Diabetes Institute, 2Department of Physiology, Anatomy and Microbiology, La Trobe University, 3Florey Institute of Neuroscience and Mental Health, University of Melbourne, 4Department of Physiology, Centre for Muscle Research (CMR), The University of Melbourne, 5Department of Diabetes, Central Clinical School, Monash University, 6Baker Department of Cardiometabolic Health, The University of Melbourne, 7Department of Physiology and Department of Medicine Alfred Hospital, Monash University A comprehensive laboratory protocol and analysis workflow are described for a rapid, cost-effective, and straightforward colorimetric cell-based assay to detect neutralizing elements against AAV6.