Rational design of highly active sgRNAs for CRISPR-Cas9–mediated gene inactivation

Analysis of the genome editing activity of more than 1800 sgRNAs in mouse and human cells yields rules to facilitate design of highly active RNA guides for Cas-9 genome editing. Components of the prokaryotic clustered, regularly interspaced, short palindromic repeats (CRISPR) loci have recently been repurposed for use in mammalian cells1,2,3,4,5,6. The CRISPR-associated (Cas)9 can be programmed with a single guide RNA (sgRNA) to generate...