GenCrispr NLS-Cas9-EGFP is a fusion protein developed by GenScript. It contains a nuclear localization sequence (NLS) on its N terminal and EGFP on the C terminal. Cas9 nuclease is an RNA-guided endonuclease that can catalyze cleavage of double stranded DNA. This kind of targeted nuclease is a powerful tool for genome editing with high precision. Cas9 protein forms a very stable ribonucleoprotein (RNP) complex with the guide RNA (gRNA) component of the CRISPR/Cas9 system. The Cas9 RNP complex can localize to the nucleus immediately upon entering the cell with the addition of a nuclear localization signal (NLS). There is no requirement for transcription and translation compared with mRNA or plasmid systems. Additionally, the Cas9 RNP complex is rapidly cleared from the cells minimizing the chance of off-target cleavage when compared to other systems (Kim, et al. 2014). The EGFP can be used as a reporter for tracking or sorting transfected cells, which enables the possibility of enriching cell populations for desired genome edits via fluorescence activated cell sorting (FACS). It significantly reduces the labor and cost associated with single cell cloning and genotyping in genome editing applications.

Product Source: GenCrispr NLS-Cas9-EGFP is produced by expression from an E. coli strain.

Key Features
-DNA-free: no external DNA added to system
-High cleavage efficiency: NLS ensures the entry of Cas9 protein into nuclei
-Low off target: transient expression of Cas9 nuclease
-Time-saving: no need for transcription and translation

Applications
-Screening for highly efficient and specific targeting gRNAs by in vitro DNA cleavage.
- In vivo gene editing when combined with a specific gRNA by electroporation or injection.