Here, we present a protocol for marker-free genome editing in Saccharomyces cerevisiae by combining PCR-based selectable marker cassettes with CRISPR-Cas9. We describe steps for generating gene deletions using MX6 markers and excising the markers by introducing a reusable guide RNA (gRNA)-Cas9 plasmid and universal repair templates, allowing multiplex removal in a single step. Final verification by PCR yields marker-free strains that can be iteratively edited using the same selectable markers. For complete details on the use and execution of this protocol, please refer to Grissom et al. 1 © 2025 The Author(s).
