CRISPR or CRISPR/Cas9 is commonly used to refer to a revolutionary gene editing technology that enables efficient and precise genomic modifications in a wide variety of organisms and tissues.


What is CRISPR genome editing?

Definition: Clustered Regularly Interspaced Short Palindromic Repeat or CRISPR was identified in a prokaryotic defence system. CRISPR are sections of genetic code containing short repetitions of base sequences followed by spacer DNA segments

How does CRISPR work?

Identified in archaea and bacteria, short nucleic acid sequences are captured from invading pathogens and integrated in the CRISPR loci amidst the repeats. Small RNAs, produced by transcription of these loci, can then guide a set of endonucleases to cleave the genomes of future invading pathogens, thereby disabling their attacks.

What is Cas9?

Definition: CRISPR associated protein 9 (Cas9) is an endonuclease used in an RNA-guided gene editing platform which uses a synthetic guide RNA to introduce a double strand break at a specific location within a strand of DNA

Cas9 was the first of several restriction nucleases (often called molecular scissors) discovered that enable CRISPR gene editing. The CRISPR-Cas9 gene editing system has since been adapted into a powerful tool that puts genome editing into the mainstream.

Gene Editing in the Lab

In the laboratory, cas9 editing is achieved by transfecting a cell with the Cas 9 protein along with a specially designed guide RNA (gRNA) that directs the cut through hybridization with its matching genomic sequence. When the cell repairs that break, errors can occur to generate a gene knockout or additional genetic modifications can be introduced. Our CRISPR technology is particularly good for the efficient generation of complete knockout of genes on multiple alleles.

CRISPR gene editing: How it works

Use of wild-type Cas 9 has been shown to lead to off-target cleavage, but a modified version introduces only single strand “nicks” to the DNA, which in pairs still stimulate the repair mechanisms while significantly decreasing the risk of off-target cutting.

Horizon has licensed IP from Harvard University, the Broad Institute and ERS Genomics with the goal of being able to ensure that we will be able to offer uninterrupted use of CRISPR technologies to our customers.

Other Gene Editing Systems

Horizon's CRISPR editing knowledge includes the widely used S. Pyogenes (spCas9), and also supporting those utilising CRISPR-Cas9 protocol for S. Aureus (scCas9), Cpf1, HiFi Cas9, Nickase Cas9, Nuclease Cas9, NgAgo gDNA and even synthetic spCas9 with alternative PAM sites. Contact us for more information on the molecular biology and benefits of each Cas9 structure.

Getting started with CRISPR Genome Editing

Continue your research with our CRISPR webinars:

An introduction to CRISPR gene editing

A starter's guide to use of gene editing

Planning a CRISPR editing experiment

Maximise your chances of success with our CRISPR genome editing guide

Modifying human cell lines with CRISPR

Human cell lines, genomic modification and editing efficiencies


Barrangou R, Fremaux C, Deveau H, Richards M, Boyaval P, Moineau S, Romero DA, Horvath P. 2007. CRISPR provides acquired resistance against viruses in prokaryotes. Science 315(5819): 1709-1712.

Jinek M, Chylinski K, Fonfara I, Hauer M, Doudna JA, Charpentier E. 2012. A programmable dual-RNA-guided DNA endonuclease in adaptive bacterial immunity. Science 337(6096): 816-821.

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