WORLD NEWS
Self-blinking fluorescent molecules reveal DNA folding in living cells at 20 nm
Researchers created self-blinking fluorescent molecules called HoTs and imaged DNA folding and movement inside living cells at about 20-nanometre resolution. In chemically fixed cells, they localized individual dye molecules with about 3-nanometre precision.
This does not mean the DNA double helix was photographed at 3 nanometres inside a living person, or that a cancer test is ready. The sharpest 3-nanometre result came from preserved cells, and the patient-tissue work was an early comparison of sections from only three people with bowel cancer.
Why must the fluorescent molecules blink?
If every dye shines at once, nearby points merge into one blur. HoT probes enter cells, bind to DNA and switch on at different moments. A microscope combines the locations of light from thousands of frames to build a map much finer than an ordinary light microscope can produce.
Do 20 nm and 3 nm describe the same result?
No. STORM produced about 20-nanometre resolution in living human skin cells and cultured HeLa cancer cells. The 3-nanometre figure is MINFLUX localization precision for a single dye molecule in fixed laboratory cells. A DNA double helix is about 2 nanometres wide, but localization precision and the resolution of a completed image are not the same measure.
What did the patient tissue show?
The researchers tested paraffin-preserved sections from three people with bowel cancer. DNA in tumour areas appeared less compact and more spread out than in neighbouring healthy tissue. But a three-person exploratory sample cannot establish sensitivity or false-positive rates, and the probe stains all DNA rather than one cancer gene.
What does the AI result of 96–98% mean?
The team’s AINU program distinguished skin cells from stem cells in the new images with 96–98% accuracy. The cell types carry the same DNA sequence but fold it differently. This was not accuracy for diagnosing cancer patients, and it was not a test separating cancer from healthy tissue in an independent hospital cohort.
What must be checked next?
Researchers need to reproduce the image quality across laboratories and tissues and test whether 3-nanometre-scale work is possible in living cells. Any cancer test would require many more patients and diseases and a comparison with standard pathology. Follow-up work must also address gene-specific targeting and safety.
Primary sources and independent checks
CRG official research explanation