Design · experimental
CRISPR Guide Design
Find the guides in a target sequence and check where else they could cut. Guides are enumerated by PAM match on both strands, including guides that span the origin of a circular plasmid, which a linear scan misses. Off-target search runs against a sequence you choose as the search space, so the check reflects the construct or region you actually care about.
The human EMX1 locus — the benchmark target every off-target method is compared on — plus pBR322, a 200 kb off-target search space, an EGFP donor and phage λ for a whole-genome guide library
What it does
- 01A whole build package: guides, off-targets, the repair template, the screening PCR, the protocol and the fragments to order
- 02SpCas9 guide enumeration by PAM match on both strands
- 03Origin-spanning guides on circular sequences, which a linear scan cannot find
- 04Off-target search against a sequence you select as the search space, with mismatch tolerance
- 05Guide composition readouts, including GC content and homopolymer runs
- 06Guides written back to the map as annotations, so a chosen guide is visible in context
- 07A repair template with homology arms and a PAM-disrupting mutation, silent where the cut falls in a coding sequence
- 08Screening primers placed outside the homology arms, so the assay cannot amplify the donor instead of the locus
What it runs on
Guide search and off-target search are ports of cas-offinder and crisprScore, validated against golden vectors captured from those implementations. Scoring models still being sourced are tracked in docs/RESEARCH.md rather than approximated. The panel runs on @ports/crispr-screen, @ports/enzymes, @ports/guide, @ports/primer.
Everything runs client-side. Files are parsed in the browser and projects are saved on this machine, so an unpublished sequence is never uploaded.
Questions
- Does it find guides that cross the origin of a circular plasmid?
- Yes. Circular sequences are searched as circular, so a guide whose protospacer wraps the origin is enumerated like any other.
- What does it search for off-targets?
- A sequence you choose as the search space, for example a genomic region loaded into the project. There is no remote genome query, because the search runs in the browser.
Also searched as
CRISPR guide design online · sgRNA design tool · Cas9 guide finder · CRISPR off-target search · guide RNA design plasmid · PAM site finder · cas-offinder online · free CRISPR design software · CHOPCHOP alternative · CRISPOR alternative · Benchling CRISPR alternative · design sgRNA for a plasmid · SpCas9 NGG guide finder · Cas12a guide design · free sgRNA design without an account · knock-in design with homology arms · HDR donor design online · CRISPR screening primer design