Study paves the way towards a more precise use of CRISPR

A new Danish research project can help refine the method and is a step towards a more precise and effective use of 'genetic scissors'.

"Our study shows that, by better understanding the CRISPR/Cas9 protein and its gRNA component, we can more accurately hit and cut the DNA and thereby optimise the effectiveness of gene modification," says Yonglun Luo, associate professor at the Department of Biomedicine, Aarhus University.

Revolutionary technology

Ten years ago, researchers identified a protein in bacteria that can cut DNA, and which uses a so-called guide RNA to recognise where DNA needs to be cut. The CRISPR method has been hailed as a revolution within gene technology ever since.

CRISPR makes it possible to remove or insert the exact genes you want in any living organism -- from bacteria to plants to humans.

The CRISPR technology also makes it possible to cure diseases through the precise correction of errors appeared in our genes.

This means that the technology has an almost infinite amount of uses within basic research, public health, agriculture and medicine.

Preventing unintended modifications

Implementation of the technology will require that the method is effective and precise, so we only achieve the desired, rather than unintended, gene modifications.

To better understand the mechanisms that affect the effectiveness of the CRISPR method, researchers from the University of Copenhagen and Aarhus University have used an energy-based model to identify the mechanisms regulating CRISPR-Cas9's activity and specification.

This model makes it possible for researchers to design gRNA components that can increase the effectiveness of the method and minimise unintended effects -- also known as 'off-target effects'.

"Unintended off-targets are a major concern when using the CRISPR method to treat diseases, and most of the tools for measuring off-targets have serious limitations and do not include the factors that we have discovered in our study. These discoveries have given us the key to designing CRISPR-gRNA with high effectiveness and precision," explains Yonglun Luo.

Refining the method

The researchers behind the study will continue refining the method and the design of the gRNA component to further improve the method's effectiveness and precision.

"We'll also try to find new methods of measuring on-target and off-target areas and developing innovative methods to address the off-target challenges that still limit our ability to use the CRISPR-Cas9 method," says Yonglun Luo.