Department of Cell and Developmental Biology, University of Michigan 1 article published in JoVE Neuroscience One-step CRISPR-based Strategy for Endogenous Gene Tagging in Drosophila melanogaster Yangbo Xiao*1, Ye Yuan*2, Swathi Yadlapalli1,2,3 1Department of Cell and Developmental Biology, University of Michigan, 2Cellular and Molecular Biology Program, University of Michigan, 3Michigan Neuroscience Institute Affiliate, University of Michigan Here, we present a simplified endogenous gene tagging protocol for Drosophila, which utilizes a PCR-based technique for marker-free identification of successful genetic modifications, facilitating the development of stable knock-in lines.