Professor Kwang-il Lim's Team Develops Imaging Technology to Map Protein Binding Sites on Long DNA Molecules
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- Writer 커뮤니케이션팀
- 보도일자 2026-07-23
A collaborative research team including Professor Kwang-il Lim of the Department of Chemical and Biological Engineering has developed a single-molecule imaging technology that enables high-resolution, direct visualization of proteins bound to long DNA molecules.
The new approach combines scanning electron microscopy (SEM), chemical and biomolecular labeling, and machine learning. The technology is expected to provide an important foundation for next-generation genomic analysis, genetic diagnostics, and precision medicine.
The study was conducted in collaboration with research teams led by Professor Kyubong Jo of Sogang University, Professor Jung Heon Lee of Sungkyunkwan University, and Professor Sang-Hee Shim of Korea University. The findings were published in Nucleic Acids Research, one of the world's leading journals.
Within cells, numerous proteins bind to specific locations on DNA to regulate essential biological processes, including gene expression, DNA replication, and DNA repair. Precisely identifying where these proteins bind along long DNA molecules is therefore essential for understanding genome regulation and for advancing genomic research and gene therapy.
Existing fluorescence microscopy-based techniques have limited positional accuracy because of the diffraction limit of light. Although atomic force microscopy (AFM) offers high spatial resolution, it is not well suited for rapidly imaging long DNA molecules over large areas. Transmission electron microscopy (TEM), meanwhile, requires complex sample preparation and is less suitable for imaging extended DNA molecules, limiting its use for large-scale analysis.
To overcome these limitations, the research team developed an SEM-based DNA imaging platform. DNA molecules were stretched onto silicon substrates and treated with rare-earth-based electron staining (UranyLess) together with polymer coating to enable high-contrast visualization. Using this platform, the researchers successfully visualized specific genomic loci by labeling dCas9 proteins programmed to bind target DNA sequences.
The team also developed a machine learning-based image analysis algorithm that automatically detects and quantitatively analyzes protein binding sites, enabling more accurate and objective identification of binding locations than conventional fluorescence microscopy approaches.
Building on several years of continuous refinement of the DNA imaging platform, the collaborative research team is now pursuing follow-up studies aimed at achieving even higher-resolution analysis of DNA structures and developing next-generation genomic imaging technologies. The researchers have recently obtained promising new results and are preparing a follow-up publication.
"This technology is expected to provide an important foundation for next-generation genomic diagnostics, precision medicine, gene therapy quality control, and single-molecule genome analysis," said Professor Kwang-il Lim.
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