Imaging-based pooled CRISPR screen. Schematic of imaging-based pooled CRISPR screen. Cells expressing PA-mCherry are infected with a pooled sgRNA library and imaged using a microscope. Images are collected and analyzed automatically to generate an activation mask targeting cells of interest. Exposure with blue light photoactivates cells of interest into mCherry-positive cells that are subsequently isolated by FACS. Samples are analyzed by high-throughput sequencing for sgRNA identification.