The discovery and implementation of CRISPR/Cas9 tools in pooled genetic screens have allowed for the rapid, high-fidelity identification of host-virus interactions. However, pooled CRISPR screening has significant limitations in its ability both to perform cell biology and plate reader-based screens and to find alleles that result in intermediate-strength phenotypes. Here we introduce an arrayed CRISPR screening method, FACS-IT, which allows researchers to use high content imaging analysis, plate reader assays, cell supernatant characterization, and percent infectivity to characterize CRISPR-mediated gene disruptions causing both moderate and extreme phenotypic changes. By using flow sorting capabilities and CRISPR libraries that are widely available, FACS-IT overcomes both the significant limitation of pooled screening approaches and the prohibitive costs of large-scale arrayed CRISPR reagents. In doing so, FACS-IT will enable researchers to creatively use CRISPR screening to obtain a deeper understanding of biology across a wide range of fields and applications.
Keywords: Arrayed; CRISPR; Genetic screen; Host-virus interactions; Viral dependency; Viral restriction.