Determining optimal sgRNA coverage and screening duration for pooled CRISPR screens A quantitative framework

CRISPR-based loss-of-function screening has emerged as a powerful tool for systematically characterizing gene functions. However, standardized quantification metrics for gRNA coverage and screening duration critical parameters determining genome-wide screening reliability and resource efficiency, remain undefined. In this study, we first conducted systematic gRNA coverage tests in Hela cells to determine the optimal coverage for CRISPRiBAR knockout libraries. Furthermore, we incorporated multiple timepoints to monitor gRNA-mediated gene knockout dynamics. Our results demonstrate that 800x sgRNA coverage per sgRNAiBAR, combined with a 15-day screening duration, ensures the generation of a robust and cost-effective cell library suitable for subsequent conditional screening. Data from varying coverage levels can also serve as essential references for screening under different experimental conditions. Longitudinal analysis revealed that extending the screening period beyond 15 days maintains stable sgRNA distribution patterns within the cell population. This study establishes key parameter benchmarks to ensure CRISPRiBAR knockout screening efficacy and reproducibility, providing a solid foundation for downstream drug screening and target identification.