DNA Chip
Harvard’s silicon chip writes 64 DNA sequences in parallel using only electricity and water-based enzymes — no toxic solvents, no photomasks. Each electrode site drives electrolysis to lower local pH and trigger TdT, the enzyme that stitches nucleotides to growing strands. July 2026.
Harvard · 8×8 Enzymatic Synthesis Array
0 nt total0 selected
SELECT SITES
Click individual sites to toggle, or use the buttons above
NUCLEOTIDE
A · Adenine
PHASE LEGEND
Selected (ready)
Electrode active
pH dropping (7 → 5)
Adding A (Adenine)
Synthesis Mechanism
About the Breakthrough
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64 Sequences in Parallel
Harvard's chip synthesizes 64 distinct DNA sequences simultaneously — far beyond prior enzymatic approaches limited to ~12. Each of the 64 sites is independently addressable, enabling combinatorial DNA libraries on a single chip.
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Electrochemical pH Control
Two concentric ring electrodes surround each DNA anchor site. The inner electrode runs electrolysis, splitting H₂O to generate local protons (H⁺) — dropping pH from ~7 to ~5 and activating the enzyme only at that one spot.
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TdT: The Key Enzyme
Terminal deoxynucleotidyl transferase (TdT) appends nucleotides to single-stranded DNA at low pH, in any order, without a template. Switch the electrode off, pH neutralizes, and the enzyme stops — clean, cycle-by-cycle control.
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Water-Based Chemistry
Traditional phosphoramidite DNA synthesis uses toxic organic solvents and must be done under anhydrous conditions. This approach needs only water and enzymes — greener, safer, and compatible with biological environments.
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39 Nucleotides & Growing
The July 2026 prototype produces sequences up to 39 nt — already useful for CRISPR guide RNAs and oligonucleotide probes. Longer sequences could enable point-of-care gene therapy or DNA-based data storage at warehouse scale.