MIT and Harvard Scientists Boost Precision of Genome Editing

ISAAA August 13, 2025

Researchers from the Massachusetts Institute of Technology (MIT) and Harvard Medical School have developed a fast-acting, cell-permeable protein system that can switch off CRISPR-Cas9 after genome editing. This system could reduce the risk of harmful off-target effects and advance the safety and precision of gene therapies.

The new system, called LF_N–Acr/PA, uses a protein-based delivery system to transport anti-CRISPR proteins into human cells. “Our technology reduces the off-target activity of Cas9 and increases its genome editing specificity and clinical utility,” said Raines, the Roger and Georges Firmenich Professor of Natural Products Chemistry.

The technology boosts the specificity of genome editing by up to 40% by shutting down Cas9 activity with speed and precision. The LF_N–Acr/PA system could pave the way for faster, safer, and more controllable CRISPR-based therapies for conditions such as sickle cell disease, muscular dystrophy, and cancer.

For more information, read the article from the MIT Department of Chemistry.