New protein AcrIIA4 increases CRISPR-CAS9 precision

From This DNA-mimicking protein can make gene editing more precise and safe – The Verge

Even though gene-editing tools like CRISPR-Cas9 are very precise, they sometimes snip pieces of DNA they weren’t programmed to cut. These off-target cuts can be dangerous, and scientists have been trying to find ways to prevent them.

The researchers found that the protein AcrIIA4 mimics DNA so that it can bind to the Cas9 enzyme, blocking it from attaching to actual DNA and cutting it.

Finally, the researchers added AcrIIA4 a few hours after adding the Cas9; that prevented CRISPR from cutting DNA at the wrong sites, while still allowing time for cutting at the right sites.