Researchers show enzyme copies synthetic DNA with 99% accuracy

Researchers at the University of California San Diego have shown that a key biological enzyme can accurately read and copy an eight‑letter DNA alphabet. In a study published this month, the team demonstrated that the enzyme can recognize and replicate synthetic bases that do not exist in natural DNA, producing accurate copies of the expanded genetic sequence. The work was carried out in the lab of Dr. Sarah T. Johnson, a professor of molecular biology, and involved testing the enzyme’s fidelity across dozens of synthetic DNA strands.

The discovery is a milestone for synthetic biology, a field that seeks to redesign life’s building blocks for new purposes. For decades scientists have imagined adding extra letters to DNA to encode more information, but they have struggled to find a natural system that can handle the extra complexity. By proving that the enzyme can work with an eight‑letter alphabet, the team shows that living cells could, in principle, process and store synthetic genetic information without needing entirely new machinery. This opens the door to engineered organisms that could produce novel medicines, biofuels or materials that are impossible to make with natural DNA alone.

The paper reports that the enzyme maintained more than 99 % accuracy when copying the expanded alphabet, a level comparable to its performance with the standard four letters. Dr. Johnson said the result “confirms that the cell’s own tools are more versatile than we thought.” The team plans to test the system in living bacteria next year, hoping to create microbes that can synthesize new compounds. If successful, the technique could accelerate the development of biological factories that produce high‑value chemicals, making biomanufacturing more efficient and sustainable.