CRISPR/Cas - the system that revolutionises gene editing

by Katrin Mansperger, PhD, Business Development Manager, Eurofins Genomics

The CRISPR/Cas system is a self-defense mechanism of bacteria and archaea to fend off exogenous DNA. The ground-breaking article in Science in 2012 by Emmanuelle Charpentier, Jennifer Doudna et al. described the use of the CRISPR/Cas system as a molecular genetics tool. Since then, many researchers and companies have taken advantage of this new and easy technology to genetically modify organisms.

The mechanism behind the “molecular scissors” is the introduction of a double-stranded DNA cut at a predetermined target sequence by the Cas enzyme. The resulting double-strand break is detected by the cell’s own DNA repair processes and subsequently fixed; however, a 10 to 15 bp insertion or deletion is typically introduced.

The development of modified Cas9 enzymes and the discovery of other Cas enzymes broadens the options for gene editing. Combined with the use of specifically designed guide RNAs, it is now possible to not only introduce targeted insertions and deletions but also to introduce certain mutations and entire gene constructs.

Recently, the CRISPR/Cas9 system was used in humans in a clinical setting. A patient who suffered from betathalassemia was treated with modified stem cells. Specifically, the patient’s own hematopoietic stem cells were modified ex vivo using CRISPR/Cas9 and then re-infused into the patient’s bloodstream. An equivalent treatment is already planned for sickle cell disease.

This new approach of cell-based therapies inevitably requires a multitude of novel genomics products but also novel testing. Eurofins Genomics provides many solutions, from cloning oligos, single guide RNAs to donor DNAs in the form of synthetic genes. The success of a gene edit can be determined by Sanger sequencing, fragment length analysis, or next generation sequencing. Eurofins’ solutions are provided for research purposes, patient testing within clinical trials, and lost release testing of CRISPR modified primary cells amongst others.

For more information, visit: www.eurofinsgenomics.com