Cluster of Excellence CellNetworks 1 article published in JoVE Bioengineering Isolation of Next-Generation Gene Therapy Vectors through Engineering, Barcoding, and Screening of Adeno-Associated Virus (AAV) Capsid Variants Kleopatra Rapti1,2, Olena Maiakovska1,2, Jonas Becker1,2, Joanna Szumska1,2, Margarita Zayas1,2, Felix Bubeck1,2, Jixin Liu1,2, Emma Gerstmann1,2, Chiara Krämer1,2, Ellen Wiedtke1,2, Dirk Grimm1,2,3,4,5 1Department of Infectious Diseases/Virology, Section Viral Vector Technologies, Medical Faculty, University of Heidelberg, 2BioQuant Center, BQ0030, University of Heidelberg, 3Cluster of Excellence CellNetworks, 4German Center for Infection Research (DZIF), 5German Center for Cardiovascular Research (DZHK) AAV peptide display library generation and subsequent validation through the barcoding of candidates with novel properties for the creation of next-generation AAVs.