A Comparative Analysis of CRISPR Screening Technologies

This paper offers a general review and comparative analysis of various types of Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) technologies. It evaluates the strengths and weaknesses of these technologies to identify the optimal approach for conducting genetic screens. Through an extensive literature review, this paper examines CRISPR nuclease, CRISPR activation (CRISPRa), and CRISPR interference (CRISPRi) screens. This study concludes that CRISPRa and CRISPRi are more advantageous due to their use of deactivated Cas9 proteins that only over-express or deactivate genes rather than irreversibly breaking genes like CRISPRn. Notably, CRISPRa is unique in its ability to over-express genes, while the other two technologies deactivate genes. Future studies may focus on inducing multiple mutations simultaneously—both gain-of-function and gene knockout—to carry out a more complete screen that can test the combinatorial effect of genes. Likewise, targeting both exons and introns can offer a more thorough understanding of a specific phenotype.