RT Journal Article SR Electronic T1 Easi-CRISPR: Efficient germline modification with long ssDNA donors JF bioRxiv FD Cold Spring Harbor Laboratory SP 069963 DO 10.1101/069963 A1 Rolen M. Quadros A1 Masato Ohtsuka A1 Donald W Harms A1 Tomomi Aida A1 Ronald Redder A1 Hiromi Miura A1 Guy P. Richardson A1 Mark A. Behlke A1 Sarah A. Zeiner A1 Ashley M. Jacobi A1 Lisa D. Urness A1 Suzanne L. Mansour A1 Channabasavaiah B. Gurumurthy YR 2016 UL http://biorxiv.org/content/early/2016/08/17/069963.abstract AB CRISPR/Cas9 technology efficiently produces short insertions or deletions (indels) and can insert short exogenous sequences at Cas9 cut sites. However, targeting long inserts is still a major technical challenge. To overcome this challenge, we developed Easi-CRISPR (Efficient additions with ssDNA inserts-CRISPR), a method that uses long, in vitro-synthesized, single-stranded DNAs with 50-100 base homology arms as repair templates. We demonstrate that Easi-CRISPR can generate knock-in and floxed alleles in mice with an efficiency at many loci as high as 100%. The simple design requirements for donor DNAs and the reproducibly high-efficiency of Easi-CRISPR enables rapid development of many types of commonly used animal and cell models.