CRISPOR: intuitive guide selection for CRISPR/Cas9 genome editing experiments and screens

Abstract

CRISPOR.org is a web tool for genome editing experiments with the CRISPR-Cas9 system. It finds guide RNAs in an input sequence and ranks them according to different scores that evaluate potential off-targets in the genome of interest and predict on-target activity. The list of genomes is continuously expanded, with more 150 genomes added in the last two years. CRISPOR tries to provide a comprehensive solution from selection, cloning and expression of guide RNA as well as providing primers needed for testing guide activity and potential off-targets. Recent developments include batch design for genome-wide CRISPR and saturation screens, creating custom oligonucleotides for guide cloning and the design of next generation sequencing primers to test for off-target mutations. CRISPOR is available from http://crispor.org, including the full source code of the website and a stand-alone, command-line version.

Figure 1.

Main output of CRISPOR. At the top, a graphical representation of the input sequence with variants and CRISPR target sequences. Below, a table with guide targets, one per row, annotated with predictive scores, off-target numers and locations and a link the PCR primer designer.