IGI Co-Director Jonathan Weissman, Scientific Director Jacob Corn, Research Scientist Chong Park, and other colleagues have developed the next generation of guide RNAs (gRNAs) for high-throughput CRISPR screens. Establishing rules for the design of effective gRNAs is critical to making CRISPR activation and repression screens more specific and robust. Based on recent observations that compact DNA inhibits Cas9 access, the team tweaked their guide RNA design algorithm to target more open regions of human and mouse genomes. Taking chromatin, position, and sequence features into account allowed for the design of highly active guide RNA libraries.
gRNA library design tools are available on Github. The improved gRNA libraries will soon be available on AddGene.
Compact and highly active next-generation libraries for CRISPR-mediated gene repression and activation
eLife | September 23, 2016