ALT An overview of the CRISPR screening process. It begins with the construction of synthetic sgRNA plasmid libraries for Cas9 knockout or transcriptional activation. These plasmid libraries are then packaged into lentiviruses and transduced into the target cell lines, creating stable cell lines for screening. After selection, a diverse pool of cells with gene knockouts is obtained, which can be used in various screening methods. Genomic DNA is collected at specific time points, followed by next-generation sequencing and data analysis to identify candidate genes.