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CRISPR sgRNA Constructs and Services

The CRISPR/Cas9 system can be used for knocking out gene expression in vivo or in vitro by using a combination of an sgRNA (single guide RNA, or gRNA) along with a Cas9 nuclease. Achieve permanent 100% knockout in your cell line by using Cellecta’s lentiviral-based CRISPR sgRNA constructs. Expression of the sgRNA and Cas9 is stable, and constructs can be used in dividing or non-dividing cells or whole model organisms. Let Cellecta design and make CRISPR sgRNA constructs for you or create a Custom Pooled CRISPR sgRNA Library for your system.

We offer the following CRISPR systems:

CRISPR/Cas9 knockout efficiency of two vector system CRISPR sgRNA constructs

Two-vector vs. single vector knockout efficiency. CRISPR sgRNA constructs targeting GFP were built using the Two Vector and Single Vector CRISPR systems and used to transduce cells that had been previously engineered to stably express GFP. Both CRISPR systems provide at least 80% knockout of GFP, but the two-vector system performed better with over 90% knockout. The enhanced performance is due to pre-selection of cells expressing high levels of Cas9 before transduction with the GFP sgRNA constructs.

Packaging comparison of 1-vector and 2-vector CRISPR-Cas9 sgRNA vector systems

Poor packaging of Cas9 constructs. Due to the size of the SpCas9 gene (4.1 kb), lentiviral constructs expressing the Cas9 protein are approaching the size limit for effective lentiviral packaging. As a result, the single-construct Cas9-sgRNA vectors generate less than 2% of the viral particles that standard sgRNA-only constructs do under the same packaging conditions. This difference can be seen in the figure above which shows the yield in TU/ml for the same-scale packaging of 3 different lentiviral constructs: an sgRNA-only construct, a Cas9 expressing plasmid, and a Cas9-sgRNA expression construct.