A silicon chip originally designed to study electrical activity in neurons was repurposed as a tool for a very different task: writing DNA.
Harvard researchers developed a semiconductor-based system which can produce DNA sequences simultaneously using electricity and water-based enzymes and may provide a cleaner alternative to traditional DNA manufacturing.
The new work is published in Nature Electronics and is another step in DNA synthesis that is more scalable but less dependent on dangerous chemical solvents for synthesis. The Harvard-led team demonstrated the parallel generation of 64 sequences of DNA that can be up to 39 nucleotides long.
From Neuroscience to DNA Synthesis
The technology’s unusual path started in neuroscience. The silicon chip was originally designed to record electrical activity from huge populations of neurons. Researchers came to realize that the chip’s ability to control electric currents precisely could be useful to control chemical reactions in tiny locations.
By modifying the chip's electrodes, the team turned it into a platform that can control DNA synthesis site by site. This repurposing shows how hardware designed to conduct brain research can be used in biotechnology.
Electricity Controls DNA Writing
Traditional DNA synthesis is based on phosphoramidite chemistry, which is a well-established process that employs organic solvents and special infrastructure.
While effective, the process can be hazardous and therefore difficult to develop smaller and more environmentally friendly synthesis systems.
The Harvard method instead uses enzymatic DNA synthesis in water. During this process, electricity is used to produce localized pH changes in acidity around individual sites of DNA synthesis.
These acid changes can be used by enzymes to add nucleotides to DNA strands growing.
The chip uses electrode structures to create protons at specific locations and restrict them to nearby sites. A number of DNA sequences can be programmed simultaneously on the same chip.
Why the Breakthrough Matters
Parallel DNA synthesis is important for fields ranging from biotechnology and diagnostics to synthetic biology and DNA-based data storage. Increasing the number of sequences that can be produced at once could eventually make DNA-writing technologies more practical and accessible.
However, the system is still in the experimental phase. Harvard researchers say the biggest limitation is the deprotection chemistry and not electronics. And making this more efficient would allow the technology to take advantage of much larger arrays in the future.
So the achievement is more than a faster DNA-writing technique. It shows how semiconductor technology and biology can be combined to create new laboratory platforms.
As scientists continue to improve sequence length, accuracy and parallel processing, electrically controlled DNA synthesis could become an important technology in biotechnology, diagnostics and information storage.
