CRISPR interference (CRISPRi) allows researchers to down-regulate specific gene function by blocking transcription, without editing the DNA. Visit our CRISPRi applications page to learn more.

The Horizon CRISPRmod CRISPRi system requires two components to operate: a gene-specific CRISPRi guide RNA and a catalytically deactivated Cas9 (dCas9) fused to transcriptional repressor domains (SALL1 and SDS3). Our CRISPRi reagents provide a straightforward, efficient set of tools to study a gene’s function via transcriptional repression. 


CRISPRi reagent selection

There are many options and considerations for CRISPRi experimental conditions. For extended timepoint assays (more than 120 hours), we recommend lentiviral sgRNA. For short-term assays, synthetic sgRNA typically provides more robust gene repression. 

CRISPRi dCas9-SALL1-SDS3 source Guide RNA format Delivery method Benefits & Recommended uses

CRISPRi dCas9-SALL1-SDS3 lentiviral particle
 transduction & selection for CRISPRi dCas9 stable cells

CRISPRi synthetic sgRNA Transfection or electroporation
  • Transient repression assays
  • Pool guide RNAs for increased repression
  • Multiplex targets for simultaneous knockdown 
  • Arrayed screening
CRISPRi lentiviral sgRNA Transduction
  • Stable expression for extended repression
  • Low MOI - single integration for stable and even repression
CRISPRi dCas9-SALL1-SDS3 mRNA CRISPRi synthetic sgRNA Co-transfection or electroporation
  • Rapid transient repression - Results within hours
  • Lentiviral free workflow
  • EGFP and puromycin resistance options for enrichment of dCas9-expressing cells
  • Pool guide RNAs for increased repression
  • Multiplex targets for simultaneous knockdown 
  • Ideal for working in primary cells
CRISPRi all-in-one dCas9-SALL1-SDS3 + sgRNA Transduction
  • Maximize successful delivery of CRISPRi components into difficult to transduce cell types
  • Puromycin or GFP markers allow for live cell tracking of gene interference