CRISPR or CRISPR Cas9 is commonly used to refer to a revolutionary genome editing technology that enables efficient and precise genomic modifications in a wide variety of organisms and tissues.
What is CRISPR?
Definition: Clustered Regularly Interspaced Short Palindromic Repeat or CRISPR (pronounced 'crisper') was identified in a prokaryotic defence system. CRISPR are sections of genetic code containing short repetitions of base sequences followed by spacer DNA segments
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 (Cas 9) is an endonuclease used in an RNA-guided gene editing platform. It 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 (or molecular scissors) discovered that enable CRISPR genome editing. The CRISPR Cas9 mechanism has since been adapted into a powerful tool that puts genome editing into the mainstream.
In the laboratory, CRISPR Cas9 genome editing is achieved by transfecting a cell with the Cas9 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.
Cas9 unwinds the double stranded DNA allowing the sgRNA to basepair with one strand and subsequently cleave both strands.
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.
Our CRISPR gene editing technology is particularly good for the efficient generation of complete knockout of genes on multiple alleles.
Horizon has licensed gene editing 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 tools to our customers. Our scientists have extensive knowledge of CRISPR technology including the benefits of using each Cas9 structure.
Other Gene Editing Systems
Genome editing can be achieved using the widely used S. Pyogenes (spCas9), and also utilising CRISPR Cas 9 protocol for S. Aureus (scCas9), Cpf1, HiFi Cas9, Nickase Cas9, Nuclease Cas9 and even synthetic spCas9 with alternative PAM sites.
Continue your CRIPSR/Cas9 research with our popular education and training webinars:
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.