Although CRISPR knockout screening has provided a powerful and precise solution to identify and validate novel drug targets, and to elucidate unknown drug mechanisms, there are some biological studies for which CRISPR knockout screens are not applicable. A CRISPR interference screen (CRISPRi) from Horizon Discovery can open up new opportunities for your research.

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What is CRISPRi?

CRISPR Interference (CRISPRi) screening enables us to study reduced gene expression, rather than completely eliminating gene expression. These tools provide highly precise and sensitive screening solutions. 
Horizon's CRISPRi Screening Tools


Our CRISPR interference screen enables you to:

  • Model druggability more closely
  • Study essential genes and genes in amplified loci
  • Target non-protein coding regions (e.g. lncRNA)
  • Validate hits from a KO screen with an orthologous tool
  • Combine with KO or CRISPRa screening for high sensitivity screening

CRISPRi Screening Platform

Our CRISPR interference screening platforms are based on Horizon’s highly sophisticated CRISPR KO screening platform, which has been used in over 200 screens to date.

  • Pooled lentiviral approach
  • Cell line(s) from a pre-optimised cell line list or cell line evaluation prior to the screen
  • Human whole-genome CRISPRi library or custom designed sub library
  • Custom screen design
  • Next-generation sequencing + bioinformatics analysis + hit nominations
  • Timeline 12-24 weeks
  • A list of genes of which inhibition/activation alters response to the compound of interest
  • A final report containing experimental design, all raw & analysed data and conclusions of the study

To learn more about our platforms watch our recorded webinar on CRISPRi & CRISPRa screening

Whole-genome CRISPRi resistance screens in melanoma cells


Proof of concept studies to identify resistance factors against a BRAF kinase inhibitor Vemurafenib (PLX-4032) in A375 melanoma cells that carry a BRAF V600E mutation.

  • Whole-genome CRISPRi or CRISPRa sgRNA libraries
  • Pooled-based approach: lentivirus transduction of the library into cells followed by selection
  • Treatment with Vemurafenib
  • Cell pellet collection and sample preparation
  • NGS and data analysis using an adapted MAGeCK workflow


  • Highlighted hits have been previously identified and validated by CRISPR KO screening 
  • Top hit MED12 was enriched by over 16,000-fold
  • CRISPRi screening showed very high sensitivity
  • Multiple novel hits were also identified

Download the complete application note:

CRISPRi screening app note

Get expert advice and help for your next CRISPR screening project:

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