Fig. 4

CRISPR screening using pooled DNA oligos. In the most common types of CRISPR screening, a pool of oligos is designed to target a large number of genes. A library of lentiviruses is shaped from the oligos and applied to infect cells. CRISPR genome editing ablates several genes in various cells. Next-generation sequencing (NGS) is applied to define either present or absent genes. Importantly, genes for drug resistance or sensitivity can be detected. Meanwhile, negative screens define genes eliciting resistance, while positive screens define genes eliciting sensitivity