A new study by the the Novo Nordisk Foundation Center for Protein Research details how CRISPR-Cas12a works, right down to the molecular level. This should make it possible to fine-tune the process to achieve better results.

To create this study, published in Nature, the researchers used a cryo-electron microscope to map the technology, taking photographs of the moments when CRISPR-Cas12a cuts up the DNA strand.

Among other things, the scientists found that three parts of CRISPR-Cas12a must change form for the DNA to be cut properly.

Associate Professor Nikos Hatzakis, of the Department of Chemistry and the Nano-Science Center, said the changing pieces act as “airport security checks”: “You have to complete all checks and in the right order to proceed.”

They also found that these security checks are the reason CRISPR can sometimes cause side-effects in the genome, remaining open after the DNA strand has been cut. This can cause the process to last longer than intended, with the still-running gene editing technology causing further changes.