Chari, RajMali, PrashantMoosburner, MarkChurch, George2017-03-282017Chari, Raj, Prashant Mali, Mark Moosburner, and George M. Church. 2017. “Unraveling CRISPR-Cas9 genome engineering parameters via a library-on-library approach.” Nature methods 12 (9): 823-826. doi:10.1038/nmeth.3473. http://dx.doi.org/10.1038/nmeth.3473.http://nrs.harvard.edu/urn-3:HUL.InstRepos:31731641We develop an in vivo library-on-library methodology to simultaneously assess single guide RNA (sgRNA) activity across ~1,400 genomic loci. Assaying across multiple human cell types, end-processing enzymes, and two Cas9 orthologs, we unravel underlying nucleotide sequence and epigenetic parameters. Our results enable improved design of reagents, shed light on mechanisms of genome targeting, and provide a generalizable framework to study nucleic acid-nucleic acid interactions and biochemistry in high throughput.en-USJournal Article2017-03-2810.1038/nmeth.3473