Biologists at the University of Sheffield and the University of York recorded the physical union of two genetic strands in a 2026 investigation, ending a 20-year debate over how molecules overcome identical electrostatic charges to align. Using high-resolution atomic force microscopy, the academic teams documented two double helices joining together, providing the earliest direct visual record of this cellular event.
Negative electrical charges normally force identical structures apart. Cells nevertheless require genetic sequences to unite during recombination, gene silencing, chromosome packing and oncological shifts. The charges repel.
Microscopic tracking showed brief genetic segments aligning groove by groove with absolute positional precision. Computer simulations revealed that positively charged ions of nickel, magnesium and calcium build microscopic bridges between the opposing indentations, anchoring both strands into a shared structure across the atomic gap that once separated them during cellular operations.
The paper appeared in the scientific publication Nucleic Acids Research in 2026.
Direct imagery of the pairing mechanism
Dr. Thomas Catley, co-lead author from the School of Chemical Materials and Biological Engineering at the University of Sheffield, said, “To be able to directly visualize this long-hypothesized mechanism for the first time was incredible. The advanced imaging techniques at our disposal have allowed us to uncover these key DNA interactions, which have implications for many cellular processes. It opens the door to studying other DNA interactions that, until now, have existed only as theory.”
Catley said, “Hopefully, these programmable interactions could eventually help engineers design custom DNA structures for future biotechnology, such as DNA origami, and shed light on how DNA is actually packaged inside cells.”
Professor Agnes Noy, a study leader from the School of Physics, Engineering and Technology at the University of York, stated, “This discovery could help researchers identify regions of the genome specifically involved in DNA pairing. These regions may become particularly important when mutations disrupt normal cellular processes and contribute to cancer.”
These findings validate a physical hypothesis conceived two decades ago by Professor Alexey Kornyshev of Imperial College London. His model posited that nearby mineral salts produce alternating bands of electrical charges, permitting paired helical strands to interlock like dual spiral stairs. The study resolves the mystery.
Atomic interactions bridging genetic strands
Laboratory specialists produced topographical maps of genetic samples by running atomic force microscopy probes across each specimen while computer programs traced atomic trajectories. Divalent metallic particles functioned as dual mechanical arms, gripping each double helix concurrently across the fluid barrier.
Dr. Victor Velasco-Berrelleza from the School of Mathematical and Physical Sciences at the University of Sheffield said, “While microscopy can show us what happens, it’s the simulations that allow us to uncover the molecular mechanism behind it. This mechanism could be another tool in the DNA regulatory toolkit, where some DNA sequences may not encode proteins but could instead influence where DNA molecules interact with each other, helping the genome form higher-order structures such as chromosomes.”
Variable alignment across nucleotide sequences
The research demonstrated that helical recognition varies across genome segments, creating distinct bonding zones where specific codes secure much tighter joins than neighboring units. These preferential targets dictate where chromosomal chains unite.
The University of Sheffield confirmed the experimental framework matched foundational physical research with biomedical applications.