Direct preparation of Cas9 ribonucleoproteins with an extended 'gRNA-shRNA' construct in Escherichia coli for precise genome manipulation.

Gene perturbation approaches have emerged as powerful tools for elucidating gene function and treating hereditary disorders. Previously, we developed a method for streamlined production of ready-to-use Cas9 ribonucleoproteins (RNPs) in Escherichia coli BL21(DE3). In this study, we present an improved approach by assembling Cas9 RNPs with an extended 'gRNA-shRNA' construct in the RNase III deficient strain HT115(DE3). Transfection of these engineered Cas9 RNPs into mammalian cells enables multidimensional genome manipulation, including simultaneous knockdown and knockout of target genes. Furthermore, the design of shRNA specifically targeting human DNA ligase IV (LIG4) significantly enhances efficiency in homology-directed repair genome editing. Collectively, our findings establish a user-friendly CRISPR/Cas9 RNP tool with immense potential for precise genome editing, gene function analysis, and gene therapy.